KR102296752B1 - Treatment of Cancer Cells Overexpressing Somatostatin Receptor Using an Octreotide Derivative Chelated to a Radioisotope - Google Patents

Abstract

Disclosed are cancer targeting compositions, kits and methods for treating cancer cells overexpressing the somatostatin receptor. The composition comprises a radioisotope, a chelator and a targeting moiety. Chelators include nitrogen ring structures such as tetraazacyclododecane, triazacyclononane, and/or tetraazabicyclo [6.6.2] hexadecane derivatives. The targeting moiety includes a somatostatin receptor targeting peptide. Somatostatin receptor targeting peptides include octreotide derivatives. The targeting moiety is chelated to the radioisotope by a chelator, whereby the cancer cells are targeted for clearance.
[Representative]
Figure 1A

Description

Treatment of Cancer Cells Overexpressing Somatostatin Receptor Using an Octreotide Derivative Chelated to a Radioisotope

Cross-reference of related applications

This application claims priority to U.S. Provisional Application No. 62/445,541, filed January 12, 2017, the entire contents of which are incorporated herein by reference.

background

The present disclosure relates generally to the treatment of cancer. More particularly, the present disclosure relates to targeted radiotherapy of cancer patients using radiolabeled conjugates.

Various drugs have been developed for the treatment of cancer cells. To specifically target cancer cells, targeting compositions have been developed to treat cancer cells without affecting healthy cells that may be in the vicinity of the cancer cells. To target cancer cells, the targeting composition is provided with a chemical designed to specifically bind to a portion of the cancer cell. Such compositions may be overexpressed in cancer cells compared to healthy cells. These compositions also bind to and damage cancer cells without damaging other cells in the patient.

Examples of conjugates used to treat cancer are provided in US Patents/Application Nos. 2016/0143926, 2015/0196673, 2014/0228551, 9408928, 9217009, 8858916, 7202330, 6225284, 6683162, 6358491, and WO2014052471, in their entirety. is incorporated herein by reference. Examples of tumor targeting compositions are provided in US Patent/Application Nos. US2007/0025910, and US5804157, the entire contents of which are incorporated herein by reference.

For additional information on cancer treatment, see Milenic et al., Bench to Bedside: Stability Studies of GMP Produced Trastuzumab-TCMC in Support of a Clinical Trial, Pharmaceuticals, vol. 8, pp. 435-454 (2015); Tan et al., Biodistribution of ²¹² Pb Conjugated Trastuzumab in Mice. J Radioanal Nucl. Chem., Journal of Radioanalytical and Nuclear Chemistry, April 2012; Boudousq et al., Comparison between Internalizing Anti-HER2 mAbs and Non-Internalizing Anti-CEA mAbs in Alpha-Radioimmunotherapy of Small Volume Peritoneal Carcinomatosis Using ²¹² Pb, July 2013; Dr. Fisher, Development and Testing of a ²¹² Pb/ ²¹² Bi Peptide for Targeting Metastatic Melanoma, US Department of Energy, October 2012; Meredith et al., Dose Escalation and Dosimetry of First in Human Alpha Radioimmuno-therapy with ²¹² Pb-TCMC-trastuzumab, J Nucl Med., 55(10): 1636-1642, October 2014; Elgqvist et al., The Potential and Hurdles of Targeted Alpha Therapy - Clinical Trials and Beyond, Frontiers In Oncology, January 14, 2014; Miao et al., Melanoma Therapy via Peptide-Targeted A-Radiation, Clinical Cancer Research, 11 (15), www.aacrjournals.org, August 1, 2005; Meredith et al., Pharmacokinetics and Imaging of ²¹² Pb-TCMC-Trastuzumab After Intraperitoneal Administration in Ovarian Cancer Patients, Cancer Biotherapy and Radiopharmaceuticals, Vol. 29, Number 1, (2014); Yong et al., Towards Translation of ²¹² Pb as a Clinical Therapeutic: Getting The Lead In!, National Institute of Health, Dalton Trans., 40(23), June 21, 2011; Milenic et al., Toxicological Studies of ²¹² Pb Intravenously or Intraperitoneally Injected into Mice for a Phase 1 Trial, Pharmaceuticals, vol. 8, pp. 416-434 (2015), the entire contents of which are incorporated herein by reference.

Despite advances in cancer treatment, there is a need for effective and safe targeted radiotherapy to eliminate cancer cells without damaging healthy cells in cancer patients. The present disclosure is directed to meeting these needs.

summary

In at least one aspect, the present disclosure relates to a cancer targeting composition for treating cancer cells overexpressing a somatostatin receptor. The composition comprises a radioisotope, a chelator and a targeting moiety. The chelator includes a nitrogen ring structure. The nitrogen ring structure includes derivatives selected from the group consisting of tetraazacyclododecane derivatives, triazacyclononane derivatives, and tetraazabicyclo[6.6.2]hexadecane derivatives. The targeting moiety includes a somatostatin receptor targeting peptide. The somatostatin receptor targeting peptide comprises an octreotide derivative and is conjugated to a radioisotope-coordinated chelator to target and treat cancer cells for elimination.

Disclosed herein are cancer targeting compositions for treating cancer cells overexpressing the somatostatin receptor. The cancer targeting composition comprises a radioisotope; chelators comprising a nitrogen ring structure, wherein the nitrogen ring structure includes derivatives selected from the group consisting of tetraazacyclododecane derivatives, triazacyclononane derivatives, and tetraazabicyclo[6.6.2] hexadecane derivatives; and a targeting moiety comprising a somatostatin receptor targeting peptide, wherein the somatostatin receptor targeting peptide comprises an octreotide derivative, wherein the targeting moiety is conjugated to a chelator coordinating a radioisotope, thereby targeting and treating cancer cells for elimination. box); or products thereof.

The composition has the following chemical structure:

Here, M is a radioisotope.

The composition has the following chemical structure:

Here, M is a radioisotope.

Radioisotopes include at least one of α-emitters, β-emitters, γ-emitters, positron emitters, and combinations thereof. The radioisotope ^{includes at least one of 212} Bi, ²¹² Pb, ²⁰³ Pb, and combinations thereof. A chelator has one of the following general formulas:

The radioisotope includes at least one of ⁶⁴ Cu and ^{67 Cu.} A chelator has one of the following general formulas:

Radioisotopes are ²²⁵ Ac, ²³¹ Am, ²⁴³ Am, ²¹¹ At, ²¹⁷ At, ²⁴⁷ Bk, ²¹² Bi, ²¹³ Bi, ²⁴⁸ Cf, ²⁵⁰ Cf, ²⁵¹ Cf, ²⁴⁰ Cm, ²⁴³ Cm, ²⁴⁵ Cm, ¹⁵⁴ Dy, ²⁵² Es, ²⁵³ Es, ²⁵⁵ Es, ²⁵² Fm, ²⁵³ Fm, ²²¹ Fr, ¹⁴⁸ Gd, ¹⁷⁴ Hf, ²⁵⁸ Md, ¹⁴⁴ Nd, ²³⁷ Np, ¹⁸⁶ Os, ¹⁹⁰ Pt, ²³⁶ Pu, ²³⁸ Pu, ²¹³ Pa, ²³¹ Pa, ²²³ Ra, ²²⁴ Ra, ²¹⁹ Rn, ¹⁴⁶ Sm, ¹⁴⁷ Sm, ¹⁴⁹ Tb, ²²⁷ Th, ²²⁹ Th, ²³⁰ U, ²³⁶ U, and combinations thereof. The chelator is 1,4,7,10-tetrakis(carbamoylmethyl)-1,4,7,10-tetraazacyclododecane, or 1,4,7,10-tetraazacyclododecane-1 ,4,7-tri(carbamoylmethyl)-10-acetic acid. The chelator is (2-(4-isothiocyanatobenzyl)-1,4,7,10-tetraaza-1,4,7,10-tetra-(2-carbamoylmethyl)-cyclododecane ), S-2-(4-isothiocyanatobenzyl)-1,4,7,10-tetraaza-1,4,7,10-tetra(2-carbamoylmethyl)cyclododecane, or 2-(4,7,10-tris(2-amino-2-oxoethyl)-3-(4-isothiocyanatobenzyl)-1,4,7,10-tetraazacyclododecane-1- 1) Contains acetic acid. The cancer targeting composition further comprises a linker, wherein the targeting moiety is chelated to the radioisotope via the linker to the chelator. Linkers include at least one of straight chain (C ₁ -C ₆ )alkyl, branched chain (C ₁ -C ₆ )alkyl, polyethylene glycol, and combinations thereof. In one embodiment, the octreotide derivative is a conjugate of octreotate (HD-Phe-Cys-Phe-D-Trp-Lys-Thr-Cys-Thr-OH, C ₄₉ H ₆₄ N ₁₀ O ₁₁ S ₂ ), (Tyr3)-octreotate conjugate, octreotide (H ₂ ND-Phe-Cys-Phe-D-Trp-Lys-Thr-Cys-Thr-ol, C ₄₉ H ₆₆ N ₁₀ O ₁₀ S ₂ ), and combinations thereof. The cancer targeting composition further comprises an end group selected from the group consisting of methylcarboxyl, acetamide, alkane, alkene, acetic acid, and carboxylamine.

Disclosed herein are cancer targeting kits for treating cancer cells overexpressing the somatostatin receptor. Cancer targeting kits include radioisotopes; chelators comprising a nitrogen ring structure, wherein the nitrogen ring structure includes derivatives selected from the group consisting of tetraazacyclododecane derivatives, triazacyclononane derivatives, and tetraazabicyclo[6.6.2] hexadecane derivatives; and a targeting moiety comprising a somatostatin receptor targeting peptide, wherein the somatostatin receptor targeting peptide comprises an octreotide derivative, wherein the targeting moiety is chelated to the radioisotope by a chelator that coordinates the radioisotope, whereby the cancer cell is released. targeting and treating for elimination), or a cancer targeting composition comprising a product thereof; and buffers.

The cancer targeting kit contains 25-50 μg of the cancer targeting composition and 0.4M ammonium acetate. In one embodiment, the buffer comprises an ammonium acetate buffer. The cancer targeting kit further comprises an antioxidant, which is at least one selected from the group consisting of ascorbic acid, gentisic acid, ethanol, and combinations thereof. The cancer targeting kit further comprises a scavenger, which is diethylenetriaminopentaacetic acid, diethylenetriaminepentaacetic acid, ethylenediaminetetraacetic acid, 1,4,7,10-tetraazacyclododecane-1,4 ,7,10-tetraacetic acid, and combinations thereof.

Disclosed herein are methods for the targeted treatment of cancer cells overexpressing the somatostatin receptor. The method comprises a radioisotope; chelators comprising a nitrogen ring structure, wherein the nitrogen ring structure includes derivatives selected from the group consisting of tetraazacyclododecane derivatives, triazacyclononane derivatives, and tetraazabicyclo[6.6.2] hexadecane derivatives; and a targeting moiety comprising a somatostatin receptor targeting peptide, wherein the somatostatin receptor targeting peptide comprises an octreotide derivative and the targeting moiety is chelated to a radioisotope by a chelator, thereby targeting cancer cells for elimination. providing a cancer targeting composition comprising or a product thereof; and administering the cancer targeting composition to a patient having cancer cells.

The method further comprises binding the targeting moiety to the cancer cell. The method further comprises uptake of the cancer targeting composition by the cancer cells. The method further comprises disrupting the radioisotope by releasing beta particles. ^{The decay involves the decay of 212} Pb to ²¹² Bi by releasing beta particles and the decay of ²¹² Bi to ²⁰⁸ Ti by releasing alpha particles. In one embodiment of the method, the disruption occurs within or on the surface of the cancer cell. The method further comprises killing the cancer cell by the alpha particle. The method further comprises removing the cancer targeting composition from the patient.

The composition may have the following chemical structure:

Here, M is a radioisotope. Each of the compositions comprises ((4R,7S,10S,13R,16S,19R)-13-((1H-indol-3-yl)methyl)-10-(4-aminobutyl)-16- chelated to M (4-hydroxybenzyl)-7-((R)-1-hydroxyethyl)-6,9,12,15,18-pentaoxo-19-((R)-3-phenyl-2-(2) -(4,7,10-tris(2-amino-2-oxoethyl)-1,4,7,10-tetraazacyclododecan-1-yl)acetamido)propanamido)-1,2 -dithia-5,8,11,14,17-pentaazacycloicosan-4-carbonyl)-L-threonine; 2,2′,2″-(10-(2-(((R)-1-(((4R,7S,10S,13R,16S,19R)-13-((1H-indole) chelated to M) -3-yl)methyl)-10-(4-aminobutyl)-4-(((2R,3R)-1,3-dihydroxybutan-2-yl)carbamoyl)-16-(4- Hydroxybenzyl)-7-((R)-1-hydroxyethyl)-6,9,12,15,18-pentaoxo-1,2-dithia-5,8,11,14,17-penta Azacycloicosan-19-yl)amino)-1-oxo-3-phenylpropan-2-yl)amino)-2-oxoethyl)-1,4,7,10-tetraazacyclododecan-1, 4,7-triyl)triacetamide; or ((4R,7S,10S,13R,16S,19R)-13-((1H-indol-3-yl)methyl)-10-( 4-Aminobutyl)-16-(4-hydroxybenzyl)-7-((R)-1-hydroxyethyl)-6,9,12,15,18-pentaoxo-19-((R)- 3-phenyl-2-(3-(4-(((S)-1,4,7,10-tetrakis(2-amino-2-oxoethyl)-1,4,7,10-tetraazacyclo dodecan-2-yl)methyl)phenyl)thioureido)propanamido)-1,2-dithia-5,8,11,14,17-pentaazacycloicosan-4-carbonyl)- It may have the chemical structure of L-threonine, where M is a radioisotope.

Within the context of the present invention, the term "radioisotope" as used herein includes ions thereof. Thus, it is understood by those skilled in the art that, for example, the terms lead, Pb, ²¹² Pb or ²⁰³ Pb are intended to encompass the ionic form of the radioisotope.

Radioisotopes may include α-emitters, β-emitters, γ-emitters, and/or positron emitters. Radioisotopes are ²¹² Bi, ²¹² Pb, ²⁰³ Pb, ⁶⁴ Cu, ⁶⁷ Cu, ²²⁵ Ac, ²³¹ Am, ²⁴³ Am, ²¹¹ At, ²¹⁷ At, ²⁴⁷ Bk, ²¹² Bi, ²¹³ Bi, ²⁴⁸ Cf, ²⁵⁰ Cf, ²⁵¹ Cf, ²⁴⁰ Cm, ²⁴³ Cm, ²⁴⁵ Cm, ¹⁵⁴ Dy, ²⁵² Es, ²⁵³ Es, ²⁵⁵ Es, ²⁵² Fm, ²⁵³ Fm, ²²¹ Fr, ¹⁴⁸ Gd, ¹⁷⁴ Hf, ²⁵⁸ Md, ¹⁴⁴ Nd, ²³⁷ Np, ¹⁸⁶ Os, ¹⁹⁰ Pt, ²³⁶ Pu, ²³⁸ Pu, ²¹³ Pa, ²³¹ Pa, ²²³ Ra, ²²⁴ Ra, ²¹⁹ Rn, ¹⁴⁶ Sm, ¹⁴⁷ Sm, ¹⁴⁹ Tb, ²²⁷ Th, ²²⁹ Th, ²³⁰ U and/or ²³⁶ U have.

A chelator may have one of the following general formulas:

The chelators are each 2-(4,7,10-tris(2-amino-2-oxoethyl)-1,4,7,10-tetraazacyclododecan-1-yl)acetic acid; 2,2',2",2"'-(2-(4-isothiocyanatobenzyl)-1,4,7,10-tetraazacyclododecan-1,4,7,10-tetrayl ) tetraacetamide; 2-(4,7,10-tris(2-amino-2-oxoethyl)-3-(4-isothiocyanatobenzyl)-1,4,7,10-tetraazacyclododecane-1- day) acetic acid; 6-(2-(4,7,10-tris(2-(methylamino)-2-oxoethyl)-1,4,7,10-tetraazacyclododecan-1-yl)acetamido)hexane Mountain; 2,2',2",2"'-((2,2',2",2"'-(2-(4-isothiocyanatobenzyl)-1,4,7,10-tetraaza cyclododecane-1,4,7,10-tetrayl)tetrakis(acetyl))tetrakis(azanediyl))tetraacetic acid; 2,2',2"-(4-(4-isothiocyanatobenzyl)-3,6,9-triaza-1(2,6)-pyridinacyclodecapan-3,6,9- triyl)triacetic acid;2,2′,2″-(2-(4-isothiocyanatobenzyl)-1,4,7-triazonan-1,4,7-triyl)triacetic acid; 2,2′,2″-(10-(2-((2,5-dioxopyrrolidin-1-yl)oxy)-2-oxoethyl)-1,4,7,10-tetraazacyclodo Decane-1,4,7-triyl)triacetic acid and 2-(11-(carboxymethyl)-1,4,8,11-tetraazabicyclo[6.6.2]hexadecan-4-yl)-4 -(4-isothiocyanatophenyl)butanoic acid The chelator is DOTAM (1,4,7,10-tetrakis(carbamoylmethyl)-1,4,7,10-tetra azacyclododecane), and/or TCMC (2-(4-isothiocyanatobenzyl)-1,4,7,10-tetraaza-1,4,7,10-tetra-(2-carba) moylmethyl)-cyclododecane).

The cancer targeting composition may also include a linker. The targeting moiety may be chelated to the radioisotope via a linker. Linkers may include straight chain C ₁ -C ₆ alkyl, branched chain C ₁ -C ₆ alkyl, and/or polyethylene glycol.

Octreotide derivatives include octreotate (HD-Phe-Cys-Phe-D-Trp-Lys-Thr-Cys-Thr-OH, C ₄₉ H ₆₄ N ₁₀ O ₁₁ S ₂ ), (Tyr3)-octreotate a conjugate of, an octreotide (H ₂ ND-Phe-Cys-Phe-D-Trp-Lys-Thr-Cys-Thr-ol, and/or C ₄₉ H ₆₆ N ₁₀ O ₁₀ S ₂ ). . The cancer targeting composition may also include an end group. The end groups can be methylcarboxyl, acetamide, alkane, alkene, acetic acid, and/or carboxylamine. Unless otherwise indicated, the term “octreotide derivative” refers to an octreotide having one or more end groups selected from the group consisting of methylcarboxyl, acetamide, alkane, alkene, acetic acid, and/or carboxylamine.

In another aspect, the present disclosure relates to a cancer targeting kit for treating cancer cells overexpressing the somatostatin receptor. The kit includes a cancer targeting composition and a buffer for treating cancer cells overexpressing a somatostatin receptor. The composition comprises a radioisotope, a chelator and a targeting moiety. Chelators include nitrogen ring structures. The nitrogen ring structure may include, but is not limited to, tetraazacyclododecane derivatives, triazacyclononane derivatives, and tetraazabicyclo[6.6.2]hexadecane derivatives such as, but not limited to, 2-(4,7,10-tris(2-amino-). 2-oxoethyl)-1,4,7,10-tetraazacyclododecan-1-yl)acetic acid; 2,2',2",2"'-(2-(4-isothiocyanatobenzyl)-1,4,7,10-tetraazacyclododecan-1,4,7,10-tetrayl ) tetraacetamide; 2-(4,7,10-tris(2-amino-2-oxoethyl)-3-(4-isothiocyanatobenzyl)-1,4,7,10-tetraazacyclododecane-1- day) acetic acid; 6-(2-(4,7,10-tris(2-(methylamino)-2-oxoethyl)-1,4,7,10-tetraazacyclododecan-1-yl)acetamido)hexane Mountain; 2,2',2",2"'-((2,2',2",2"'-(2-(4-isothiocyanatobenzyl)-1,4,7,10-tetraaza cyclododecane-1,4,7,10-tetrayl)tetrakis(acetyl))tetrakis(azanediyl))tetraacetic acid; 2,2',2"-(4-(4-isothiocyanatobenzyl)-3,6,9-triaza-1(2,6)-pyridinacyclodecapan-3,6,9- triyl)triacetic acid;2,2′,2″-(2-(4-isothiocyanatobenzyl)-1,4,7-triazonan-1,4,7-triyl)triacetic acid; 2,2′,2″-(10-(2-((2,5-dioxopyrrolidin-1-yl)oxy)-2-oxoethyl)-1,4,7,10-tetraazacyclodo Decane-1,4,7-triyl)triacetic acid and 2-(11-(carboxymethyl)-1,4,8,11-tetraazabicyclo[6.6.2]hexadecan-4-yl)-4 -(4-isothiocyanatophenyl)butanoic acid, DOTAM (1,4,7,10-tetrakis(carbamoylmethyl)-1,4,7,10-tetraazacyclododecane), and/ or TCMC (2-(4-isothiocyanatobenzyl)-1,4,7,10-tetraaza-1,4,7,10-tetra-(2-carbamoylmethyl)-cyclododecane) Derivatives selected from the group consisting of

The targeting moiety includes a somatostatin receptor targeting peptide. The somatostatin receptor targeting peptide comprises an octreotide derivative, which is conjugated to a radioisotope-coordinated chelator to target and treat cancer cells for elimination. The kit may also include antioxidants and/or scavengers. The cancer targeting composition may comprise about 25 to about 50 μg of the cancer targeting composition and about 0.4M ammonium acetate.

In another aspect, the present disclosure relates to a method for the targeted treatment of cancer cells overexpressing the somatostatin receptor. The method comprises providing a cancer targeting composition and administering the cancer targeting composition to a patient having cancer cells. The composition comprises a radioisotope, a chelator and a targeting moiety. Chelators include nitrogen ring structures. The nitrogen ring structure includes derivatives selected from the group consisting of tetraazacyclododecane derivatives, triazacyclononane derivatives, and tetraazabicyclo[6.6.2]hexadecane derivatives. Unless otherwise indicated, the term "derivative" as used in reference to a nitrogen ring refers to a nitrogen ring structure having one or more end groups selected from the group consisting _{of CH 2} C(=O)-OH and CH ₂ C(=O)-NH _{2 .} refers to For example, tetraazacyclododecane derivatives, triazacyclononane derivatives, and tetraazabicyclo[6.6.2] hexadecane derivatives contain at least one nitrogen in which at least one nitrogen is CH ₂ C(=O)—OH and CH ₂ C(= tetraazacyclododecane, triazacyclononane, and tetraazabicyclo[6.6.2] hexadecane, having a terminal group selected from the group consisting of O)—NH _{2 .}

The targeting moiety includes a somatostatin receptor targeting peptide. The somatostatin receptor targeting peptide comprises an octreotide derivative, which is conjugated to a chelator that coordinates a radioisotope, to target and treat cancer cells for elimination.

This overview also includes the features shown in the drawings.

Brief description of the drawing
The present disclosure may be more particularly described with reference to the embodiments shown in the accompanying drawings. It should be noted, however, that the accompanying drawings illustrate examples and are therefore not to be considered limiting of their scope. The drawings are not necessarily to scale, and certain features and specific illustrations of the drawings may be shown exaggerated in scale or diagrammatically for clarity and brevity.
1A and 1B are schematic diagrams illustrating various configurations of cancer targeting compositions comprising a somatostatin receptor targeting chelator-conjugate.
2A1 - 2A4 and 2B1 - 2B4 are exemplary chemical structures of chelators of cancer targeting compositions.
3A and 3B are exemplary chemical structures of functional groups of cancer targeting compositions.
4A and 4B are exemplary chemical structures of linkers of cancer targeting compositions.
5A-5B are exemplary chemical structures of cancer targeting compositions comprising DOTATOC and DOTATATE, respectively.
6A-6C show an _{acetamide end group with a methylcarboxyl end group (CH 2} -C(=O)-OH), an acetamide end group (CH ₂ -C(=O)-NH ₂ ), and a linker, respectively. It is an exemplary chemical structure of a cancer targeting composition comprising a.
7A-7C are chromatographs depicting the radiochemical stability of ^{203 Pb-DOTAMTATE conjugates.}
8A-8B are chromatographs depicting the radiochemical stability of ^{203 Pb-TCMCTATE.}
9 is a graph depicting cellular uptake (% ID/g) of ²⁰³ Pb-DOTAMTATE and ²⁰³ Pb-TCMCTATE in AR42J cancer cell line.
10 is a graph depicting cellular uptake and competition results of ²⁰³ Pb-DOTAMTATE and ²⁰³ Pb-DOTATATE in AR42J cancer cell line in vitro.
11 is a ^{graph depicting a comparison of cellular uptake of 203} Pb-DOTAMTATE and ²⁰³ Pb-TCMCTATE with increased accumulation of radiolabeled agonists tested at various agonist doses.
12 is a graph showing the results of the biodistribution of ²⁰³ Pb-DOTAMTATE and ²⁰³ Pb-TCMCTATE in non-tumor bearing mice, measured after injection.
13 is a graph depicting the results of the biodistribution of ²⁰³ Pb acetate in non-tumor bearing mice, measured after injection.
14 is a graph showing the results of the biodistribution of ²¹² Pb-DOTAMTATE in AR42J tumor bearing mice over time.
15 is a graph depicting a comparison of the biodistribution results of ²¹² Pb-DOTAMTATE in the CB17-SCID strain of AR42J tumor bearing mice over time.
16 is a graph showing the results of the biodistribution of ²⁰³ Pb-DOTAMTATE in athymic nude mice over time.
^{17 is a graph depicting the results of the biodistribution of 212} Pb-DOTAMTATE in female and male AR42J mice at 4 and 24 hours, and FIG. 17B compares male and female renal retention of octreotides over time. It is a graph showing
17A and 17B are graphs of comparison of male and female kidney retention of octreotides over time. Mean uptake (% IA/g) ^{of [ 111} In-DTPA] octreotide in the kidneys of female and male rats (B) and mice (C) at 4, 24, 96 and 168 h pi. Rats (n=2 per group) received 6 MBq/0.5 μg of radiolabeled peptide and mice (n=4 per group) received 10 MBq/0.1 μg of radiolabeled peptide. Differences in renal uptake between female and male mice were significant at all time points (P<.001) (Melis et al., 2007).
18 is a graph depicting the results of a ²¹² Pb-DOTAMTATE efficacy study in a dose range experiment performed in AR42J xenograft tumor-bearing mice over time.
19A-19B are graphs depicting the effect of a control (cold DOTAMTATE or phosphate buffer-PBS) on tumor growth volume for each xenograft mouse.
20A-20E are graphs depicting the results of the effect of a dose of ²¹² Pb-DOTAMTATE on tumor growth volume for each xenograft mouse.
21 is a schematic diagram illustrating a kit and method of making a cancer targeting composition for administration to a cancer patient.
22 is a flow chart depicting a method of targeted radiotherapy of cancer cells.
23 is a graph of binding of ²¹² Pb-DOTAMTATE to AR42J cells. ^{Binding of 212} Pb-DOTAMTATE to AR42J cells is measured with increasing counts per minute (cpm) as the level of drug increases. Average for 4 wells per group and 250,000 cells per well.
24 is a graph of cytotoxicity of AR42J cells treated with ^{212 Pb-DOTAMTATE.} AR42J tumor size shows a certain level of variability in the athymic nude strain. Three groups were prepared such that each group had the same mean tumor size. Outliers in each group are indicated by an asterisk (*).
25 is a graph of AR42J tumor volume on the day of injection. AR42J tumor size shows a certain level of variability in the athymic nude strain. Three groups were prepared such that each group had the same mean tumor size. Outliers in each group are indicated by an asterisk (*).
26 is a graph of tumor uptake and tumor volume correlation. The % ID/g of each of the 5 animals in each time point group is shown (1 hour, 4 hours, 24 hours).
27 is a graph of the effect of intrinsic activity on tumor uptake in athymic nude mice. ^{% ID/g of each group at three different intrinsic activities of 212} Pb-DOTAMTATE are shown: 10 μCi per 4.1 ng, n=3, 10 μCi per 22 ng, from left to right for each organ, n =4 and 10 μCi per 110 ng, n=3.
28A-28C are graphs of individual efficacy of mice treated with ^{212 Pb-DOTAMTATE at 2 cycle intervals.} Figures show: Figure 28A: saline alone, Figure 28B: 3 x 10 μCi-2w; and FIG. 28C 3×10 μCi-3w.
29 is a graph of Kaplan Meier survival curves of mice treated with ^{212 Pb-DOTAMTATE.}
30 is ^{a graph of 212} Pb-DOTAMTATE clearance in blood. % ID of ²¹² Pb-DOTAMTATE in the blood of CD-1 mice at 15 min, 1 h and 4 h post injection.
^{31 is a graph of 212} Pb-DOTAMTATE biodistribution in CD-1 mice. ^{Biodistribution of 212} Pb-DOTAMTATE in CD-1 mice. 15 min after injection, n=5; 1 hour, n=8; 4 hours, n=7; 24 hours, n=8; and % ID/g for the mean of three studies in numerous organs at 48 hours, n=5.
32 is a graph of the biodistribution of ²¹² Pb-DOTAMTATE and ²⁰³ Pb-DOTAMTATE in CD-1 mice. ²¹² Pb-DOTAMTATE and ²⁰³ Pb-DOTAMTATE biodistribution in CD-1 mice at 4 and 24 hours post drug injection. Values are shown in % ID/g.
33 is ^{a graph of 212} Pb-DOTAMTATE cumulative excretion in mice. Cumulative excretion of ²¹² Pb-DOTAMTATE in urine and feces over time. The % ID of drug in urine and feces are shown at 1 h, 2 h, 3 h, 4 h, 5 h, 6 h and 24 h after drug injection.
34A and 34B are ^{graphs of 212} Pb-DOTAMTATE biodistribution using a renal protectant. Nephroprotectant is co-injected with ²¹² Pb-DOTAMTATE in CD-1 mice. Shown are the % ID/g of ²¹² Pb-DOTAMTATE for use of no nephroprotectant, 2.5% lys-arg mixture, aminomedics or clinazole in various organs at 1 hour (34A) and 4 hours (34B) post injection.
Figure 35 is a graph of Kaplan-Meier survival curve - acute toxicity of ^{212 Pb-DOTAMTATE treated mice.} Kaplan-Meier survival curves of ^{212 Pb-DOTAMTATE treated mice.} Animals received a single dose ^{of 212} Pb-DOTAMTATE of 10 μCi, 20 μCi, 40 μCi or 60 μCi. Survival of animals on days post injection during the 4 week study is shown.
36 is a graph of body weight of single dose acute toxicity study mice treated with ^{212 Pb-DOTAMTATE.} Body weight of mice treated with a single dose ^{of 212} Pb-DOTAMTATE of 10 μCi, 20 μCi, 40 μCi or 60 μCi (shown in grams). Mice were weighed three times a week over the course of one month of study.
^{37 is a graph of a split dose versus a single dose 212} Pb-DOTAMTATE toxicity study in tumor-free CD-1 mice. PBS alone, n=10; 1 x 40 μCi, n=10; 2 x 20 μCi, n=10; and 3×15 μCi, n=10 Kaplan-Meier curves of the treatment group. Drug cycles 1, 2 and 3 are shown as gray dots.
38 is a graph of leukocyte counts - single versus split ²¹² Pb-DOTAMTATE. White blood cell counts are shown for animals treated with PBS alone, 1×40 μCi, 2×20 μCi and 3×15 μCi ^{212 Pb-DOTAMTATE.} Drug cycles 1, 2 and 3 are shown as gray dots.
39 is a graph of red blood cell counts - ²¹² Pb-DOTAMTATE at single versus divided doses. Red blood cell counts for animals treated with PBS alone, 1 x 40 μCi, 2 x 20 μCi and 3 x 15 μCi ^{212 Pb-DOTAMTATE are shown.} Drug cycles 1, 2 and 3 are shown as gray dots.
^{40 is a graph of 212} Pb-DOTATOC biodistribution in female CD-1 mice. ^{Biodistribution of 212} Pb-DOTATOC in CD-1 mice. 10 μCi of drug was administered and organs were collected from 3 mice per time point: 30 minutes and 4 hours post injection.
41 is a graph of a radiometric plot of ²¹² Pb-DOTATOC overlaid by a DOTATOC system suitability chromatogram. The HPLC chromatogram shows the retention time of DOTATOC alone at 5.357 min, and ^{an overlay of the plotted 212P} b DOTATOC fraction shows the peak activity (CPM) at 6.5 min.
42A-42F include graphs of individual efficacy of ²¹² Pb-DOTAMTATE and ADRUCIL ^® treated mice at 2-week and 3-week intervals.
43 is a graph of Kaplan Meier survival curves in mice treated with ^{212 Pb-DOTAMTATE.}

details

The following description includes exemplary devices, methods, techniques, and/or instructions for practicing the techniques of the present invention. However, the described embodiments may be practiced without these specific details.

Disclosed herein are cancer targeting compositions for treating cancer cells overexpressing the somatostatin receptor. The cancer targeting composition comprises a molecule of formula (I) or a pharmaceutically acceptable salt thereof:

Formula (I) M-Ch-L ₁ -Tm

here,

M is ²¹² Pb, ²⁰³ Pb, ⁶⁴ Cu, ⁶⁷ Cu, ²¹² Bi, ⁶⁸ Ga, ²¹³ Bi, ²²⁵ Ac, ²⁴³ Am, ²¹¹ At, ²¹⁷ At, ¹⁵⁴ Dy, ¹⁴⁸ Gd, ¹⁴⁶ Sm, ¹⁴⁷ Sm, ¹⁴⁹ Tb, ²²⁷ Th, ²²⁹ Th, ⁵⁹ Fe, ⁶⁰ Cu, ⁶¹ Cu, ⁶² Cu, ⁶⁷ Ga, ⁸⁶ Y, ¹¹¹ In, ¹⁵³ Gd, ¹⁵³ Sm and ¹⁶⁶ Ho;

Ch is a chelator having a structure selected from the group consisting of Formula (II), Formula (III), Formula (IV) and Formula (V):

Formula (II)

Formula (III)

Formula (IV)

Formula (V)

here,

R ⁵ , R ⁶ and R ⁸ are each independently H, D, F, Cl, (C ₁ -C ₆ )alkyl, (C ₁ -C ₆ )alkyl-C(=O)-OR ²⁵ , and (C ₁ -C ₆ )alkyl-C(=O)-N(-R ²⁵ )-R ²⁶ ;

R ⁹ , R ¹⁰ , R ¹¹ , R ¹² , R ¹⁵ , R ¹⁶ , R ¹⁷ , R ¹⁸ , R ¹⁹ , R ²⁰ , R ²¹ , R ²² , R ²³ and R ²⁴ are each independently H, D, F , Cl and (C ₁ -C ₆ )alkyl;

R ⁷ is independently H, D, F, Cl, (C ₁ -C ₆ )alkyl, (C ₁ -C ₆ )alkyl-C(=O)-N(-R ²⁵ )-R ²⁶ and L ₁ . is selected from the group consisting of;

R ¹³ and R ¹⁴ are each independently selected from the group consisting of H, D, F, Cl, (C ₁ -C ₆ )alkyl and L ^{1 ;}

R ²⁵ and R ²⁶ are each independently selected from the group consisting of H, D, (C ₁ -C ₆ )alkyl, and (C ₁ -C ₆ )alkyl-C(=O)-OH;

L ¹ is independently (C ₁ -C ₆ )alkyl-C(=O)-NH-(C ₁ -C ₆ )alkyl-C(=O)-NH, (C ₁ -C ₆ )alkyl-(C ₆ H ₄ )-NH-C(=S)-NH, C(-CO ₂ H)-(C ₁ -C ₆ )alkyl-(C ₆ H ₄ )-NH-C(=S)-NH, ( C ₁ -C ₆ )alkyl-C(=O)-NH, (C ₁ -C ₆ )alkyl-C(=O)-(O-CH ₂ -CH ₂ ) _1-20 -C(=O)- selected from the group consisting of NH;

Tm has the structure of formula (VI):

Formula (VI)

wherein R ²⁷ is independently _{selected from the group consisting of CH 2} -OH and C(=O)-OH;

However, only one of R ⁷ , R ^{13 ,} or R ¹⁴ is L ¹ . The use of L ¹ unless otherwise indicated in parentheses is L ¹ is, for example, but not officially part of the Tm, is shown to indicate the point of attachment associated as part of Tm.

The cancer targeting composition may have one, two or three ^{of R 5} , R ⁶ and R ⁸ _{being (C 1} -C ₆ )alkyl-C(=O)-N(-R ²⁵ )-R ²⁶ . M is ²¹² Pb, ²⁰³ Pb, ⁶⁴ Cu, ⁶⁷ Cu, ²¹² Bi, ²²⁵ Ac, ²⁴³ Am, ²¹¹ At, ²¹⁷ At, ¹⁵⁴ Dy, ¹⁴⁸ Gd, ¹⁴⁶ Sm, ¹⁴⁷ Sm, ¹⁴⁹ Tb, ²²⁷ Th, ²²⁹ Th, ⁵⁹ Fe, ⁶⁰ Cu, ⁶¹ Cu, ⁶² Cu, ⁶⁷ Ga, ⁸⁶ Y, ¹¹¹ In, ¹⁵³ Gd, ¹⁵³ Sm and ¹⁶⁶ Ho. M may be independently selected from the group consisting ^{of 212} Pb, ²⁰³ Pb, ⁶⁴ Cu and ^{67 Cu.} M may be selected from the group consisting ^{of 212} Pb, ²⁰³ Pb, ⁶⁴ Cu, ⁶⁷ Cu and ^{212 Bi;} Ch may have the structure of formula (V); R ²⁷ is CH ₂ —OH. M may also be selected from the group consisting of ²¹² Pb, ²⁰³ Pb, ⁶⁴ Cu, ⁶⁷ Cu, ²¹² Bi and ^{213 Bi;} Ch may have the structure of formula (V) and R ²⁷ is C(=O)—OH. A molecule of formula (I) is produced by reacting at least one compound with a chelator, wherein the chelator is

is selected from the group consisting of

The cancer targeting composition may have a structure represented by formula (VII) or a pharmaceutically acceptable salt thereof:

Formula (VII)

here,

M is ²¹² Pb, ²⁰³ Pb, ⁶⁴ Cu, ⁶⁷ Cu, ²¹² Bi, ⁶⁸ Ga, ²¹³ Bi, ²²⁵ Ac, ²⁴³ Am, ²¹¹ At, ²¹⁷ At, ¹⁵⁴ Dy, ¹⁴⁸ Gd, ¹⁴⁶ Sm, ¹⁴⁷ Sm, ¹⁴⁹ Tb, ²²⁷ Th, ²²⁹ Th, ⁵⁹ Fe, ⁶⁰ Cu, ⁶¹ Cu, ⁶² Cu, ⁶⁷ Ga, ⁸⁶ Y, ¹¹¹ In, ¹⁵³ Gd, ¹⁵³ Sm and ¹⁶⁶ Ho;

R ⁵ , R ⁶ and R ⁸ are each independently H, D, F, Cl, (C ₁ -C ₆ )alkyl, (C ₁ -C ₆ )alkyl-C(=O)-OR ²⁵ , and (C ₁ -C ₆ )alkyl-C(=O)-N(-R ²⁵ )-R ²⁶ ;

R ⁹ , R ¹⁰ , R ¹¹ , R ¹² , R ¹⁵ , R ¹⁶ , R ¹⁷ , R ¹⁸ , R ¹⁹ , R ²⁰ , R ²¹ , R ²² , R ²³ and R ²⁴ are each independently H, D, F , Cl and (C ₁ -C ₆ )alkyl;

R ¹³ and R ¹⁴ are each independently selected from the group consisting of H, D, F, Cl and (C ₁ -C _{6 )alkyl;}

R ²⁵ and R ²⁶ are each independently selected from the group consisting of H, D, (C ₁ -C ₆ )alkyl, and (C ₁ -C ₆ )alkyl-C(=O)-OH;

L ¹ is independently (C ₁ -C ₆ )alkyl-C(=O)-NH-(C ₁ -C ₆ )alkyl-C(=O)-NH, (C ₁ -C ₆ )alkyl-(C ₆ H ₄ )-NH-C(=S)-NH, C(-CO ₂ H)-(C ₁ -C ₆ )alkyl-(C ₆ H ₄ )-NH-C(=S)-NH, ( C ₁ -C ₆ )alkyl-C(=O)-NH, and (C ₁ -C ₆ )alkyl-C(=O)-(O-CH ₂ -CH ₂ ) _1-20 -C(=O) is selected from the group consisting of -NH;

wherein R ²⁷ is independently _{selected from the group consisting of CH 2} -OH and C(=O)-OH.

The cancer targeting composition may have a structure represented by formula (VIII) or a pharmaceutically acceptable salt thereof:

Formula (VIII)

here,

M is ²¹² Pb, ²⁰³ Pb, ⁶⁴ Cu, ⁶⁷ Cu, ²¹² Bi, ⁶⁸ Ga, ²¹³ Bi, ²²⁵ Ac, ²⁴³ Am, ²¹¹ At, ²¹⁷ At, ¹⁵⁴ Dy, ¹⁴⁸ Gd, ¹⁴⁶ Sm, ¹⁴⁷ Sm, ¹⁴⁹ Tb, ²²⁷ Th, ²²⁹ Th, ⁵⁹ Fe, ⁶⁰ Cu, ⁶¹ Cu, ⁶² Cu, ⁶⁷ Ga, ⁸⁶ Y, ¹¹¹ In, ¹⁵³ Gd, ¹⁵³ Sm and ¹⁶⁶ Ho;

R ⁵ , R ⁶ and R ⁸ are each independently H, D, F, Cl, (C ₁ -C ₆ )alkyl, (C ₁ -C ₆ )alkyl-C(=O)-OR ²⁵ , and (C ₁ -C ₆ )alkyl-C(=O)-N(-R ²⁵ )-R ²⁶ ;

R ⁹ , R ¹⁰ , R ¹¹ , R ¹² , R ¹⁵ , R ¹⁶ , R ¹⁷ , R ¹⁸ , R ¹⁹ , R ²⁰ , R ²¹ , R ²² , R ²³ and R ²⁴ are each independently H, D, F , Cl and (C ₁ -C ₆ )alkyl;

R ⁷ is independently H, D, F, Cl, (C ₁ -C ₆ )alkyl, and (C ₁ -C ₆ )alkyl-C(=O)-N(-R ²⁵ )-R ²⁶ is selected from;

R ¹³ is independently selected from the group consisting of H, D, F, Cl and (C ₁ -C _{6 )alkyl;}

R ²⁵ and R ²⁶ are each independently selected from the group consisting of H, D, (C ₁ -C ₆ )alkyl, and (C ₁ -C ₆ )alkyl-C(=O)-OH;

L ¹ is (C ₁ -C ₆ )alkyl-(C ₆ H ₄ )-NH—C(=S)—NH;

wherein R ²⁷ is independently _{selected from the group consisting of CH 2} -OH and C(=O)-OH.

The cancer targeting composition may have the structure of Formula (IX): or a pharmaceutically acceptable salt thereof:

Formula (IX)

here,

M is ²¹² Pb, ²⁰³ Pb, ⁶⁴ Cu, ⁶⁷ Cu, ²¹² Bi, ⁶⁸ Ga, ²¹³ Bi, ²²⁵ Ac, ²⁴³ Am, ²¹¹ At, ²¹⁷ At, ¹⁵⁴ Dy, ¹⁴⁸ Gd, ¹⁴⁶ Sm, ¹⁴⁷ Sm, ¹⁴⁹ Tb, ²²⁷ Th, ²²⁹ Th, ⁵⁹ Fe, ⁶⁰ Cu, ⁶¹ Cu, ⁶² Cu, ⁶⁷ Ga, ⁸⁶ Y, ¹¹¹ In, ¹⁵³ Gd, ¹⁵³ Sm and ¹⁶⁶ Ho;

R ⁵ , R ⁶ and R ⁸ are each independently H, D, F, Cl, (C ₁ -C ₆ )alkyl, (C ₁ -C ₆ )alkyl-C(=O)-OR ²⁵ , and (C ₁ -C ₆ )alkyl-C(=O)-N(-R ²⁵ )-R ²⁶ ;

R ⁹ , R ¹⁰ , R ¹¹ , R ¹² , R ¹⁵ , R ¹⁶ , R ¹⁷ , R ¹⁸ , R ¹⁹ , R ²⁰ , R ²¹ , R ²² , R ²³ and R ²⁴ are each independently H, D, F , Cl and (C ₁ -C ₆ )alkyl;

R ¹³ and R ¹⁴ are each independently selected from the group consisting of H, D, F, Cl and (C ₁ -C _{6 )alkyl;}

R ²⁵ and R ²⁶ are each independently selected from the group consisting of H, D, (C ₁ -C ₆ )alkyl, and (C ₁ -C ₆ )alkyl-C(=O)-OH;

wherein R ²⁷ is independently _{selected from the group consisting of CH 2} -OH and C(=O)-OH.

The cancer targeting composition may have the structure of Formula (X): or a pharmaceutically acceptable salt thereof:

Formula (X)

here,

M is ²¹² Pb, ²⁰³ Pb, ⁶⁴ Cu, ⁶⁷ Cu, ²¹² Bi, ⁶⁸ Ga, ²¹³ Bi, ²²⁵ Ac, ²⁴³ Am, ²¹¹ At, ²¹⁷ At, ¹⁵⁴ Dy, ¹⁴⁸ Gd, ¹⁴⁶ Sm, ¹⁴⁷ Sm, ¹⁴⁹ Tb, ²²⁷ Th, ²²⁹ Th, ⁵⁹ Fe, ⁶⁰ Cu, ⁶¹ Cu, ⁶² Cu, ⁶⁷ Ga, ⁸⁶ Y, ¹¹¹ In, ¹⁵³ Gd, ¹⁵³ Sm and ¹⁶⁶ Ho;

R ⁵ , R ⁶ and R ⁸ are each independently H, D, F, Cl, (C ₁ -C ₆ )alkyl, (C ₁ -C ₆ )alkyl-C(=O)-OR ²⁵ , and (C ₁ -C ₆ )alkyl-C(=O)-N(-R ²⁵ )-R ²⁶ ;

R ⁹ , R ¹⁰ , R ¹¹ , R ¹² , R ¹⁵ , R ¹⁶ , R ¹⁷ , R ¹⁸ , R ¹⁹ , R ²⁰ , R ²¹ , R ²² , R ²³ and R ²⁴ are each independently H, D, F , Cl and (C ₁ -C ₆ )alkyl;

R ⁷ is independently H, D, F, Cl, (C ₁ -C ₆ )alkyl, and (C ₁ -C ₆ )alkyl-C(=O)-N(-R ²⁵ )-R ²⁶ is selected from;

R ¹³ is independently selected from the group consisting of H, D, F, Cl and (C ₁ -C _{6 )alkyl;}

R ²⁵ and R ²⁶ are each independently selected from the group consisting of H, D, and (C ₁ -C ₆ )alkyl, and (C ₁ -C ₆ )alkyl-C(=O)-OH;

wherein R ²⁷ is independently _{selected from the group consisting of CH 2} -OH and C(=O)-OH.

The composition may comprise a molecule of formula (I) or a pharmaceutically acceptable salt thereof:

Formula (I) M-Ch-L ₁ -Tm

here,

M is ²¹² Pb, ²⁰³ Pb, ⁶⁴ Cu, ⁶⁷ Cu, ²¹² Bi, ⁶⁸ Ga, ²¹³ Bi, ²²⁵ Ac, ²⁴³ Am, ²¹¹ At, ²¹⁷ At, ¹⁵⁴ Dy, ¹⁴⁸ Gd, ¹⁴⁶ Sm, ¹⁴⁷ Sm, ¹⁴⁹ Tb, ²²⁷ Th, ²²⁹ Th, ⁵⁹ Fe, ⁶⁰ Cu, ⁶¹ Cu, ⁶² Cu, ⁶⁷ Ga, ⁸⁶ Y, ¹¹¹ In, ¹⁵³ Gd, ¹⁵³ Sm and ¹⁶⁶ Ho;

Ch is a chelator having the structure of formula (V):

Formula (V)

here,

R ⁵ , R ⁶ and R ⁸ are each independently H, D, F, Cl, (C ₁ -C ₆ )alkyl, (C ₁ -C ₆ )alkyl-C(=O)-OR ²⁵ , and (C ₁ -C ₆ )alkyl-C(=O)-N(-R ²⁵ )-R ²⁶ ;

R ⁹ , R ¹⁰ , R ¹¹ , R ¹² , R ¹⁵ , R ¹⁶ , R ¹⁷ , R ¹⁸ , R ¹⁹ , R ²⁰ , R ²¹ , R ²² , R ²³ and R ²⁴ are each independently H, D, F , Cl and (C ₁ -C ₆ )alkyl;

R ⁷ is independently H, D, F, Cl, (C ₁ -C ₆ )alkyl, (C ₁ -C ₆ )alkyl-C(=O)-N(-R ²⁵ )-R ²⁶ and L ₁ . is selected from the group consisting of;

R ¹³ and R ¹⁴ are each independently selected from the group consisting of H, D, F, Cl, (C ₁ -C ₆ )alkyl and L ^{1 ;}

R ²⁵ and R ²⁶ are each independently selected from the group consisting of H, D, (C ₁ -C ₆ )alkyl, and (C ₁ -C ₆ )alkyl-C(=O)-OH;

L ¹ is independently (C ₁ -C ₆ )alkyl-C(=O)-NH-(C ₁ -C ₆ )alkyl-C(=O)-NH, (C ₁ -C ₆ )alkyl-(C ₆ H ₄ )-NH-C(=S)-NH, C(-CO ₂ H)-(C ₁ -C ₆ )alkyl-(C ₆ H ₄ )-NH-C(=S)-NH, ( C ₁ -C ₆ )alkyl-C(=O)-NH, (C ₁ -C ₆ )alkyl-C(=O)-(O-CH ₂ -CH ₂ ) _1-20 -C(=O)- selected from the group consisting of NH;

Tm has the structure of formula (VI):

Formula (VI)

wherein R ²⁷ is CH ₂ —OH;

However, only one of R ⁷ , R ^{13 ,} or R ¹⁴ is L ¹ .

Disclosed herein are cancer targeting kits for treating cancer cells overexpressing the somatostatin receptor. A cancer targeting kit may include a cancer targeting composition disclosed herein, and at least one of a pharmaceutically acceptable buffer, antioxidant and scavenger. The cancer targeting kit may include 25-50 μg of the cancer targeting composition and 0.4M ammonium acetate buffer. The cancer targeting kit may include an ammonium acetate buffer. In one embodiment, the buffer comprises an ammonium acetate buffer. The antioxidant may include ascorbic acid, gentisic acid, ethanol, or a combination thereof. The scavenger is diethylenetriaminopentaacetic acid; ethylene diamine tetraacetic acid; 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid; and combinations thereof.

Pharmaceutical formulations are disclosed herein. The pharmaceutical formulation may comprise a cancer targeting composition disclosed herein and a pharmaceutically acceptable buffer. Disclosed is a cancer targeting composition disclosed herein for use as a medicament for treating cancer cells overexpressing the somatostatin receptor.

Disclosed herein are methods of administering to a subject in need thereof a cancer targeting composition for treating cancer cells overexpressing the somatostatin receptor to a subject in need thereof. The method may comprise administering a therapeutically effective dose of a cancer targeting composition, wherein the cancer targeting composition comprises a molecule of Formula (I) or a pharmaceutically acceptable salt thereof:

where M is ²¹² Pb, ²⁰³ Pb, ^64C u, ⁶⁷ Cu, ²¹² Bi, ⁶⁸ Ga, ²¹³ Bi, ²²⁵ Ac, ²⁴³ Am, ²¹¹ At, ²¹⁷ At, ¹⁵⁴ Dy, ¹⁴⁸ Gd, ¹⁴⁶ Sm, ¹⁴⁷ Sm, ¹⁴⁹ Tb, ²²⁷ Th, ²²⁹ Th, ⁵⁹ Fe, ⁶⁰ Cu, ⁶¹ Cu, ⁶² Cu, ⁶⁷ Ga, ⁸⁶ Y, ¹¹¹ In, ¹⁵³ Gd, ¹⁵³ Sm and ¹⁶⁶ Ho;

Ch is a chelator having a structure selected from the group consisting of Formula (II), Formula (III), Formula (IV) and Formula (V):

Formula (II)

Formula (III)

Formula (IV)

Formula (V)

here,

R ⁵ , R ⁶ and R ⁸ are each independently H, D, F, Cl, (C ₁ -C ₆ )alkyl, (C ₁ -C ₆ )alkyl-C(=O)-OR ²⁵ , and (C ₁ -C ₆ )alkyl-C(=O)-N(-R ²⁵ )-R ²⁶ ;

R ⁹ , R ¹⁰ , R ¹¹ , R ¹² , R ¹⁵ , R ¹⁶ , R ¹⁷ , R ¹⁸ , R ¹⁹ , R ²⁰ , R ²¹ , R ²² , R ²³ and R ²⁴ are each independently H, D, F , Cl and (C ₁ -C ₆ )alkyl;

R ⁷ is independently H, D, F, Cl, (C ₁ -C ₆ )alkyl, (C ₁ -C ₆ )alkyl-C(=O)-N(-R ²⁵ )-R ²⁶ and L ₁ . is selected from the group consisting of;

R ¹³ and R ¹⁴ are each independently selected from the group consisting of H, D, F, Cl, (C ₁ -C ₆ )alkyl and L ^{1 ;}

R ²⁵ and R ²⁶ are each independently selected from the group consisting of H, D, and (C ₁ -C ₆ )alkyl, and (C ₁ -C ₆ )alkyl-C(=O)-OH;

L ¹ is independently (C ₁ -C ₆ )alkyl-C(=O)-NH-(C ₁ -C ₆ )alkyl-C(=O)-NH, (C ₁ -C ₆ )alkyl-(C ₆ H ₄ )-NH-C(=S)-NH, C(-CO ₂ H)-(C ₁ -C ₆ )alkyl-(C ₆ H ₄ )-NH-C(=S)-NH, ( C ₁ -C ₆ )alkyl-C(=O)-NH, and (C ₁ -C ₆ )alkyl-C(=O)-(O-CH ₂ -CH ₂ ) _1-20 -C(=O) is selected from the group consisting of -NH;

Tm has the structure of formula (VI):

Formula (VI)

wherein R ²⁷ is independently _{selected from the group consisting of CH 2} -OH and C(=O)-OH;

However, only one of R ⁷ , R ^{13 ,} or R ¹⁴ is L ¹ .

The cancer may include cells that overexpress the somatostatin receptor. The cancer may include heart cancer, lung cancer, gastrointestinal cancer, genitourinary tract cancer, liver cancer, bone cancer, nervous system cancer, gynecological cancer, blood cancer, or a combination thereof. The subject can be a human, dog, cat, horse, or other mammal. The cancer targeting composition may be administered in combination with at least one anticancer compound, wherein the at least one anticancer compound comprises: aldesleukin; alemtuzumab; alitretinoin; allopurinol; altretamine; amifostine; anastrozole; arsenic trioxide; asparaginase; raw BCG; bexarotene capsules; bexarotene gel; bleomycin; intravenous busulfan; oral busulfan; calusterone; capecitabine; carboplatin; carmustine; Carmustine and Polypeproic Acid 20 Implant; celecoxib; chlorambucil; cisplatin; cladribine; cyclophosphamide; cytarabine; liposomal cytarabine; dacarbazine; dactinomycin, actinomycin D; darbepoetin alfa; liposomal daunorubicin; daunorubicin, daunomycin; denileukin diftitox, dexrazoxane; docetaxel; doxorubicin; liposomal doxorubicin; dromostanolone propionate; Elliott B solution; epirubicin; epoetin alpha estramustine; etoposide phosphate; etoposide (VP-16); exemestane; filgrastim; floxuridine (intraarterial); fludarabine; fluorouracil (5-FU); fulvestrant; gemcitabine; gemtuzumab ozogamicin; Gleevec (imatinib); goserelin acetate; hydroxyurea; ibritumomab tiuxetane; idarubicin; ifosfamide; imatinib mesh plate; interferon alpha-2a; interferon alpha-2b; irinotecan; letrozole; leucovorin; levamisole; Lomustine (CCNU); mechlorethamine (nitrogen mustard); megestrol acetate; melphalan (L-PAM); mercaptopurine (6-MP); Mesna; methotrexate; methoxsalen; mitomycin C; Mitotan; mitoxantrone; nandrolone fenpropionate; nofetumomab; LOddC; Ofrelbekin; oxaliplatin; paclitaxel; pamidronate; pegademase; pegaspargase; pegfilgrastim; pentostatin; pipobroman; plicamycin; mithramycin; porfimer sodium; procarbazine; quinacrine; Rasburicase; rituximab; Sargramostim; streptozocin; surafenib; talbuvidin (LDT); talc; tamoxifen; Tarceva (erlotinib); temozolomide; teniposide (VM-26); testolactone; thioguanine (6-TG); thiotepa; topotecan; toremifene; tositumomab; trastuzumab; tretinoin (ATRA); uracil mustard; valrubicin; valtorcitabine (monoval LDC); vinblastine; vinorelbine; zoledronate; or mixtures thereof. The anticancer compound may be administered at a therapeutically effective dose.

Disclosed are methods of administering to a subject in need thereof a cancer targeting composition for treating cancer cells overexpressing the somatostatin receptor to a subject in need thereof. The method comprises a therapeutically effective dose of a molecule of formula (I) or a pharmaceutically acceptable salt thereof; and at least one anticancer compound in a pharmaceutically acceptable carrier, wherein the molecule of formula (I) is:

Formula (I) M-Ch-L ₁ -Tm

where M is ²¹² Pb, ²⁰³ Pb, ⁶⁴ Cu, ⁶⁷ Cu, ²¹² Bi, ⁶⁸ Ga, ²¹³ Bi, ²²⁵ Ac, ²⁴³ Am, ²¹¹ At, ²¹⁷ At, ¹⁵⁴ Dy, ¹⁴⁸ Gd, ¹⁴⁶ Sm, ¹⁴⁷ Sm, ¹⁴⁹ Tb , ²²⁷ Th, ²²⁹ Th, ⁵⁹ Fe, ⁶⁰ Cu, ⁶¹ Cu, ⁶² Cu, ⁶⁷ Ga, ⁸⁶ Y, ¹¹¹ In, ¹⁵³ Gd, ¹⁵³ Sm and ¹⁶⁶ Ho;

Ch is a chelator having a structure selected from the group consisting of Formula (II), Formula (III), Formula (IV) and Formula (V):

Formula (II)

Formula (III)

Formula (IV)

Formula (V)

here,

R ⁵ , R ⁶ and R ⁸ are each independently H, D, F, Cl, (C ₁ -C ₆ )alkyl, (C ₁ -C ₆ )alkyl-C(=O)-OR ²⁵ , and (C ₁ -C ₆ )alkyl-C(=O)-N(-R ² 5)-R ²⁶ ;

R ⁹ , R ¹⁰ , R ¹¹ , R ¹² , R ¹⁵ , R ¹⁶ , R ¹⁷ , R ¹⁸ , R ¹⁹ , R ²⁰ , R ²¹ , R ²² , R ²³ and R ²⁴ are each independently H, D, F , Cl and (C ₁ -C ₆ )alkyl;

R ⁷ is independently H, D, F, Cl, (C ₁ -C ₆ )alkyl, (C ₁ -C ₆ )alkyl-C(=O)-N(-R ²⁵ )-R ²⁶ and L ₁ . is selected from the group consisting of;

R ¹³ and R ¹⁴ are each independently selected from the group consisting of H, D, F, Cl, (C ₁ -C ₆ )alkyl and L ^{1 ;}

R ²⁵ and R ²⁶ are each independently selected from the group consisting of H, D, (C ₁ -C ₆ )alkyl, and (C ₁ -C ₆ )alkyl-C(=O)-OH;

L ¹ is independently (C ₁ -C ₆ )alkyl-C(=O)-NH-(C ₁ -C ₆ )alkyl-C(=O)-NH, (C ₁ -C ₆ )alkyl-(C ₆ H ₄ )-NH-C(=S)-NH, C(-CO ₂ H)-(C ₁ -C ₆ )alkyl-(C ₆ H ₄ )-NH-C(=S)-NH, ( C ₁ -C ₆ )alkyl-C(=O)-NH, (C ₁ -C ₆ )alkyl-C(=O)-(O-CH ₂ -CH ₂ ) _1-20 -C(=O)- selected from the group consisting of NH;

Tm has the structure of formula (VI):

Formula (VI)

wherein R ²⁷ is independently _{selected from the group consisting of CH 2} -OH and C(=O)-OH;

However, only one of R ⁷ , R ^{13 ,} or R ¹⁴ is L ¹ .

The at least one anti-cancer compound includes aldesleukin; alemtuzumab; alitretinoin; allopurinol; altretamine; amifostine; anastrozole; arsenic trioxide; asparaginase; raw BCG; bexarotene capsules; bexarotene gel; bleomycin; intravenous busulfan; oral busulfan; calusterone; capecitabine; carboplatin; carmustine; Carmustine and Polypeproic Acid 20 Implant; celecoxib; chlorambucil; cisplatin; cladribine; cyclophosphamide; cytarabine; liposomal cytarabine; dacarbazine; dactinomycin, actinomycin D; darbepoetin alfa; liposomal daunorubicin; daunorubicin, daunomycin; denileukin diftitox, dexrazoxane; docetaxel; doxorubicin; liposomal doxorubicin; dromostanolone propionate; Elliott B solution; epirubicin; epoetin alpha estramustine; etoposide phosphate; etoposide (VP-16); exemestane; filgrastim; floxuridine (intraarterial); fludarabine; fluorouracil (5-FU); fulvestrant; gemcitabine; gemtuzumab ozogamicin; Gleevec (imatinib); goserelin acetate; hydroxyurea; ibritumomab tiuxetane; idarubicin; ifosfamide; imatinib mesh plate; interferon alpha-2a; interferon alpha-2b; irinotecan; letrozole; leucovorin; levamisole; Lomustine (CCNU); mechlorethamine (nitrogen mustard); megestrol acetate; melphalan (L-PAM); mercaptopurine (6-MP); Mesna; methotrexate; methoxsalen; mitomycin C; Mitotan; mitoxantrone; nandrolone fenpropionate; nofetumomab; LOddC; Ofrelbekin; oxaliplatin; paclitaxel; pamidronate; pegademase; pegaspargase; pegfilgrastim; pentostatin; pipobroman; plicamycin; mithramycin; porfimer sodium; procarbazine; quinacrine; Rasburicase; rituximab; Sargramostim; streptozocin; surafenib; talbuvidin (LDT); talc; tamoxifen; Tarceva (erlotinib); temozolomide; teniposide (VM-26); testolactone; thioguanine (6-TG); thiotepa; topotecan; toremifene; tositumomab; trastuzumab; tretinoin (ATRA); uracil mustard; valrubicin; valtorcitabine (monoval LDC); vinblastine; vinorelbine; zoledronate; or combinations or mixtures thereof. In one embodiment of the method, at least one anti-cancer compound is administered at a therapeutically effective dose.

Formula (I) or a pharmaceutically acceptable salt thereof, wherein at least one ^{of R 5} , R ⁶ and R ⁸ _{is (C 1} -C ₆ )alkyl-C(=O)-OR ²⁵ , and R ²⁵ is H or (C ₁ -C ₆ ) may include those that are alkyl.

Formula (I) or a pharmaceutically acceptable salt thereof, wherein at least one ^{of R 5} , R ⁶ and R ⁸ _{is (C 1} -C ₆ )alkyl-C(=O)-N(-R ²⁵ )-R ²⁶ , R ²⁵ and R ²⁶ are each independently selected from the group consisting of H and (C ₁ -C _{6 )alkyl.} Preferably, when M is ²¹³ Bi, R ⁵ , R ⁶ and R ⁸ are not C ₁ alkyl-C(=O)—OH. Preferably, when M is ²¹³ Bi, 1, 2 or 3 of ^{R 5} , R ⁶ and R ⁸ _{are CH 2} -C(=O)-NH ₂ .

Formula (I) or a pharmaceutically acceptable salt thereof is R ⁹ , R ¹⁰ , R ¹¹ , R ¹² , R ¹⁵ , R ¹⁶ , R ¹⁷ , R ¹⁸ , R ¹⁹ , R ²⁰ , R ²¹ , R ²² , R ²³ and ^{at least one of R 24} is each independently selected from the group consisting of H and (C ₁ -C _{6 )alkyl.} Formula (I) or a pharmaceutically acceptable salt thereof is R ⁹ , R ¹⁰ , R ¹¹ , R ¹² , R ¹⁵ , R ¹⁶ , R ¹⁷ , R ¹⁸ , R ¹⁹ , R ²⁰ , R ²¹ , R ²² , R ²³ And ^{at least one of R 24} may include that each independently selected from the group consisting of H and D.

In formula (I) or a pharmaceutically acceptable salt thereof, M may be independently selected from the group consisting ^{of 212} Pb, ²⁰³ Pb, ⁶⁴ Cu and ^{67 Cu;} Ch is of formula (V), wherein R ⁵ , R ⁶ and R ⁸ are (C ₁ -C ₆ )alkyl-C(=O)-N(-R ²⁵ )-R ²⁶ ; R ⁹ , R ¹⁰ , R ¹¹ , R ¹² , R ¹⁵ , R ¹⁶ , R ¹⁷ , R ¹⁸ , R ¹⁹ , R ²⁰ , R ²¹ , R ²² , R ²³ and R ²⁴ are each independently selected from H or D become; R ⁷ is L ¹ ; L ¹ is (C ₁ -C ₆ )alkyl-C(=O)—NH; R ¹³ and R ¹⁴ are each independently selected from the group consisting of H and D; R ²⁵ and R ²⁶ are each independently selected from the group consisting of H and D; Tm has the structure of formula (VI); R ²⁷ is C(=O)-OH.

In formula (I) or a pharmaceutically acceptable salt thereof, M may be independently selected from the group consisting ^{of 212} Pb, ²⁰³ Pb, ⁶⁴ Cu and ^{67 Cu;} Ch is of formula (V), wherein R ⁵ , R ⁶ and R ⁸ are (C ₁ -C ₆ )alkyl-C(=O)-N(-R ²⁵ )-R ²⁶ ; R ⁹ , R ¹⁰ , R ¹¹ , R ¹² , R ¹⁵ , R ¹⁶ , R ¹⁷ , R ¹⁸ , R ¹⁹ , R ²⁰ , R ²¹ , R ²² , R ²³ and R ²⁴ are each independently selected from H or D become; R ⁷ is (C ₁ -C ₆ )alkyl-C(=O)-N(-R ²⁵ )-R ²⁶ ; R ¹³ is independently selected from the group consisting of H and D; R ¹⁴ is L ¹ ; L ¹ is (C ₁ -C ₆ )alkyl-(C ₆ H ₄ )-NH—C(=S)—NH; R ²⁷ is C(=O)-OH.

The term "alkyl" by itself or as part of another substituent means, unless otherwise specified, a straight, branched (chiral or achiral) or cyclic chain hydrocarbon having the specified number of carbon atoms (e.g. (C ₁ -C ₆ ) means 1 to 6 carbons), straight-chain, branched-chain or cyclic groups. Examples include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl, neopentyl, hexyl, cyclohexyl and cyclopropylmethyl, such as ethyl, methyl and isopropyl in particular. This term is used in both substituent and linker groups.

Depending on the context, parentheses used in formulas may convey branching related information as a single line. For example, (C ₁ -C ₆ )alkyl-C(=O)-OH is also

로 표현될 수 있거나, 또는

can be expressed as, or

(C ₁ -C ₆ )alkyl-(C ₆ H ₄ )-NH-C(=S)-NH is

로 표현될 수 있다.

can be expressed as

Unless otherwise indicated, (C ₆ H ₄ ) refers to a benzyl group having two substituents, wherein the two substituents may be meta, ortho or para substituted.

Disclosed herein are cancer targeting kits for treating cancer cells overexpressing the somatostatin receptor. A cancer targeting kit for treating cancer cells overexpressing a somatostatin receptor comprises a cancer targeting composition of formula (I), (VII), (VIII), (IX) and/or (X) as defined above, or a pharmaceutically acceptable composition thereof. salt; and at least one of a pharmaceutically acceptable buffer, antioxidant, and scavenger. The cancer targeting kit contains 25-50 μg of the cancer targeting composition and 0.4M ammonium acetate buffer. In the cancer targeting kit, the buffer comprises an ammonium acetate buffer. In the cancer targeting kit, the antioxidant comprises ascorbic acid, gentisic acid, ethanol, or a combination thereof. In the cancer targeting kit, the scavenger is diethylenetriaminopentaacetic acid; ethylene diamine tetraacetic acid; 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid; and combinations thereof.

Pharmaceutical formulations are disclosed. The pharmaceutical agent comprises a cancer targeting composition of formula (I), (VII), (VIII), (IX) and/or (X) as defined above, or a pharmaceutically acceptable salt thereof; and pharmaceutically acceptable buffers.

Disclosed herein is a cancer targeting composition for use as a medicament for treating cancer cells overexpressing the somatostatin receptor. A cancer targeting composition for use as a medicament for treating cancer cells overexpressing a somatostatin receptor is a composition of formulas (I), (VII), (VIII), (IX) and/or (X) as defined above, or a pharmaceutical thereof phase-acceptable salts.

Disclosed herein are methods of administering to a subject in need thereof a cancer targeting composition for treating cancer cells overexpressing the somatostatin receptor to a subject in need thereof. The method comprises administering a dose of a cancer targeting composition, wherein the cancer targeting composition is a molecule of formula (I), (VII), (VIII), (IX) and/or (X) as defined above, or a pharmaceutical thereof phase-acceptable salts. The cancer may include cells that overexpress the somatostatin receptor. The cancer may include heart cancer, lung cancer, gastrointestinal cancer, genitourinary tract cancer, liver cancer, bone cancer, nervous system cancer, gynecological cancer, blood cancer, or a combination thereof. The subject can be a human, dog, cat, horse, or other mammal.

The compounds of the present invention may take the form of salts when suitably substituted with groups or atoms capable of forming salts. Such groups and atoms are well known to those skilled in the art of organic chemistry. The term “salt” encompasses addition salts of free acids or free bases that are compounds of the present invention. The term “pharmaceutically acceptable salts” refers to salts having a toxicity profile within the range providing utility in pharmaceutical applications. Pharmaceutically unacceptable salts may nevertheless have properties such as high crystallinity which have utility in the practice of the present invention, such as utility in synthesis, purification or formulation processes of the compounds of the present invention.

Suitable pharmaceutically acceptable acid addition salts may be prepared from inorganic acids or from organic acids. Examples of the inorganic acid include hydrochloric acid, hydrobromic acid, hydroiodic acid, nitric acid, carbonic acid, sulfuric acid and phosphoric acid. Suitable organic acids may be selected from the aliphatic, cycloaliphatic, aromatic, aroaliphatic, heterocyclic, carboxyl, sulfone classes of organic acids, such as formic acid, acetic acid, propionic acid, succinic acid, glycolic acid, gluconic acid, lactic acid, malic acid , tartaric acid, citric acid, ascorbic acid, glucuronic acid, maleic acid, fumaric acid, pyruvic acid, aspartic acid, glutamic acid, benzoic acid, anthranilic acid, 4-hydroxybenzoic acid, phenylacetic acid, mandelic acid, embonic acid (pamoic acid), methanesulfonic acid , ethanesulfonic acid, benzenesulfonic acid, pantothenic acid, trifluoromethanesulfonic acid, 2-hydroxyethanesulfonic acid, p-toluenesulfonic acid, sulfanilic acid, cyclohexylaminosulfonic acid, stearic acid, alginic acid, β-hydroxybutyric acid, salicylic acid, galactar acid and galacturonic acid. Examples of pharmaceutically unacceptable acid addition salts include, for example, perchlorate and tetrafluoroborate.

Suitable pharmaceutically acceptable base addition salts of the compounds of the present invention include, for example, metal salts such as alkali metal, alkaline earth metal and transition metal salts such as calcium, magnesium, potassium, sodium and zinc salts. Pharmaceutically acceptable base addition salts also include basic amines such as N,N-dibenzylethylenediamine, chloroprocaine, choline, diethanolamine, ethylenediamine, meglumine (N-methylglucamine) and procaine. organic salts prepared from Examples of pharmaceutically unacceptable base addition salts include lithium salts and cyanate salts.

The present disclosure describes compositions, kits and methods (eg, imaging, diagnosis, therapy, radiotherapy, etc.) for the treatment of neuroendocrine tumors (NETs) that overexpress somatostatin receptor (SSTR). This treatment involves chelation of a targeting moiety comprising a somatostatin receptor targeting peptide (eg, octreotate, octreotide and/or other derivatives such as “Tm”) with a chelator [CA] or “Ch”. including the use of a cancer targeting composition comprising a radioisotope (eg, α-emitter, β-emitter, γ-emitter, positron emitter and/or other radiation emitter). The chelator may have a nitrogen ring structure, such as a tetraazacyclododecane derivative, a triazacyclononane derivative and/or a tetraazabicyclo[6.6.2]hexadecane derivative (e.g., DOTAM, TCMC, DOTA, etc.). . See Tm of formula (I).

In particular, DOTAM and TCMC are used to target a radioisotope (e.g., lead (Pb) or copper (Cu)) to a targeting moiety (e.g. For example, octreotate, octreotide derivatives) can be chelated. The experiments herein show that molecules with targeting moieties and chelators (eg, DOTAM, TCMC) can selectively deliver radioisotopes to cancer cells while limiting their cytotoxic effects on healthy tissues.

Radiolabeled conjugates are derivatives of radioisotopes that recognize receptors or transporters on cancer cells and chelators that coordinate cancer-specific targeting ligands. This approach can be used to selectively deliver radioisotopes to cancer cells with limited effects on healthy cells and tissues. Compositions herein are intended to provide conjugates of chelators modified by peptide targeting SSTRs in cancer cells. The composition may be administered by injection of a solution of a radioactive complex of the composition. The conjugates described herein are intended to provide a platform for generating stable complexes with ^{α, β +} , β ^{− and/or γ-emitting radionuclides for the treatment of cancer.} The technology herein seeks to treat a disease state in a patient by administering to the patient a pharmaceutically acceptable injectable solution.

Although the methods and compositions described herein are directed to the treatment of specific cancers, they may also be applied to cardiovascular diseases, infections, diabetes, cancer and/or other conditions. When associated with cancer, the cancer is, for example, cancer of the liver, prostate, pancreas, head and neck, breast, brain, colon, adenoids, mouth, skin, lung, testis, ovary, cervix, endometrium, bladder, stomach, epithelium, etc. It may be a solid tumor derived from, for example, primary or metastatic form.

In another aspect, a cell proliferative disorder, in particular a cell proliferative disorder, comprising administering to an individual an effective amount of at least one compound according to formula (I), or a pharmaceutically acceptable salt thereof, alone or in combination with a pharmaceutically acceptable carrier A method of treating a subject suffering from cancer is provided.

In yet another aspect, the method comprises administering to the individual an effective amount of at least one compound according to formula (I), or a pharmaceutically acceptable salt thereof, alone or in combination with a pharmaceutically acceptable carrier. A method of inducing apoptosis of a cell, such as a tumor cell, is provided.

The compounds of formula (I) may be administered by any route, such as oral, rectal, sublingual, and parenteral administration. Parenteral administration includes, for example, intravenous, intramuscular, intraarterial, intraperitoneal, intranasal, intravaginal, intravesical (eg, into the bladder), intradermal, transdermal, topical or subcutaneous administration. It is also contemplated within the scope of the present invention to inject a drug into a patient's body as a controlled formulation such that systemic or local release of the drug occurs later. For example, the drug may be localized in a depot for controlled release into the circulation or for release to a local site of tumor growth.

One or more compounds useful in the practice of the present disclosure may be administered simultaneously, by the same or different routes, or at different times during treatment. The compound may be administered before, with, or after other medicaments, such as other antiproliferative compounds.

Treatments can be carried out in a single uninterrupted period or in separate periods, if desired, for longer periods of time. The treating physician will know how to increase, decrease or stop treatment based on patient response. Treatment may be performed for about 4 weeks to about 16 weeks. The treatment schedule may be repeated as needed.

targeted cancer treatment

1. DOTATATE

Cancer treatment may involve the use of a composition that targets and triggers cell death (apoptosis) of cancer cells in a patient. Some forms of targeted therapy of cancer cells may use compositions having molecules that bind to specific antigens on cancer cells. For example, targeting moieties such as low molecular weight proteins or monoclonal antibodies can be used to recognize and bind to cancer cells using specific cellular antigens that may be located on the surface of the cancer cells. Peptides can be tagged to cytotoxic agents or isotopes/metals to label them and/or induce apoptosis. Binding of peptides may enable specific recognition of cancer antigen-presenting cells that may be used for imaging and/or therapy. For example, targeting agents, such as peptides, antibodies, and antibody fragments, and the like, can be coupled with various cellular cytotoxic agents such as chemotherapeutic agents and/or other promoters of apoptosis.

Cancer targeting compositions, such as DOTATATE, can be used for the treatment of cancers that overexpress certain somatostatin receptors, such as neuroendocrine tumors (NETs). DOTATATE, as used herein, refers to a DOTA chelator conjugated to a targeting moiety, such as octreotate. DOTA, as used herein, refers to an organic compound having the formula _{(CH 2} CH ₂ NCH ₂ CO ₂ H) _{4 , 1,4,7,10-tetraazacyclododecane-1,4,7,10-} tetraacetic acid. DOTA may refer to tetracarboxylic acids and their various conjugate bases. DOTA contains a tetraaza ring of nitrogen atom with a terminal group that is immediately conjugated to the ligand. DOTA can be used as a chelator (chelating agent) for the binding of metal ions and radioisotopes. A targeting moiety as used herein refers to, for example, a peptide, protein, antibody, nucleoside, nucleotide, alcohol, heterocyclic compound and/or other ligand that binds to an antigen on a target cell, such as a cancer cell. The targeting moiety can enter the target cancer cell and induce its apoptosis.

DOTATATE includes chelators, DOTA, and coordinated metals or radioisotopes. A radioisotope may be coordinated (eg, contained, complexed) by the cancer targeting composition and selectively delivered to a cancer cell. Such coordination can be used to minimize the side effects of free radioisotopes and/or their radioactive decay products. For example, radiolabeled SSTR-ligands such as ⁹⁰ Y-DOTATOC or ¹⁷⁷ Lu-DOTATATE can be used in the treatment of NETs. Due to its potential for improved safety, DOTATATE has been used in numerous clinical trials. See, for example, Bushnell et al., 90Y-Edotreotide for Metastatic Carcinoid Refractory to Octreotide, J. Clin. Oncol., 28:1652-1659 (2010); and Kwekkeboom DJ, Bakker WH, Kam BL, et al., Treatment of Patients With Gastro-Entero-Pancreatic (GEP) Tumors With The Novel Radiolabelled Somatostatin Analogue [ ¹⁷⁷ Lu-DOTA0,Tyr3] Octreotate, European Journal of Nuclear Medicine and Molecular Imaging, 2003; 30(3):417-422, the entire contents of which are incorporated herein by reference. Experiments show positive effects such as increased median progression-free survival (mPFS) and increased disease control (DCR, proportion of patients with stable disease, partial or complete response).

As further described herein, DOTATATE is capable of chelating both diagnostic as well as precursor radioisotopes, and atoms consumed after radioactive decay, as well as any atoms in between. For example, DOTATATE may initially chelate to a radioisotope and then retain chelation of the radioisotope's decay product(s). This prevents the free (unchelated) radioisotope from dissociating from the carrier (DOTATATE) and entering the blood. The chelator is also capable of chelating radioactive isotopes consumed after decay in vivo. This may prevent potentially radioactive and/or toxic free decaying atoms from dissociating from the chelator and entering the blood.

2. DOTAMTATE and TCMCTATE

Other chelators may be used for stable coordination of isotopes, such as DOTAM, TCMC-monoacid and TCMC (as further defined herein). Such chelating agents can coordinate both diagnostic and therapeutic radioisotopes and can be used for the treatment of cancer cells. DOTAM and TCMC are similar to DOTA and have different end groups that provide, for example, increased coordination stability and increased radiochemical stability properties when used with certain radioisotopes and targeting moieties. Targeted radiotherapy may use chelators designed to retain (eg, prevent, slow dissociation, etc.) radioisotopes, such as DOTAM and TCMC, in combination with a composition such as an octreotate peptide. These compositions are intended to selectively deliver radioisotopes to target cancer cells and prevent dissociation of the radioisotopes from the chelator.

In particular, cancer targeting compositions can include DOTAM, TCMC and TCMC-monoacid chelators used in combination with radioisotopes and octreotate peptide targeting moieties to further improve therapeutic properties. Radioisotopes such as ²¹² Pb, ²⁰³ Pb, ⁶⁴ Cu and/or other radionuclide α-emitters can be used to irradiate short distances, such as within about 1-2 cell diameters and/or irreversibly damage tumor cells ( It has high linear energy transfer (LET) emission and short path lengths that may not require oxygenation or regeneration (eg, to kill).

As shown herein, these components form stable complexes with isotopes that are intended to prevent dissociation of the lead radioisotope from the conjugate under mildly acidic conditions, such as in vivo. ^{The examples herein use 212} Pb, ²⁰³ Pb or ⁶⁴ Cu as radioisotopes bound to DOTAM, TCMC and TCMC-monoacid for targeted imaging and treatment of cancer. Other radioisotopes may include, for example, iron, cobalt, zinc, and other metals having a density greater than ^{about 3.5 g/cm 3 .}

DOTAM, TCMC and TCMC-monoacid-based cancer therapeutic compositions can also form stable complexes with other radioisotopes, and thus selectively deliver radioisotopes to cancer cells to induce cytotoxic effects in normal cells. can prevent their dissociation. Because of their nature, these compositions can be used to treat NET tumors by specific cancer therapy, and SSTR expressing cancer cells are isotopes by targeting moieties such as octreotate, octreotide, or other somatostatin analogs. optionally passed to Octreotate based compounds can be used, for example, for the diagnosis of patients with SSTR-positive NETs using γ-releasing isotopes and/or using β-releasing isotopes (eg, ¹⁷⁷ Lu and ⁹⁰ Y). NET patients. See, eg, Kwekkeboom, DJ et al., Radiolabeled Somatostatin analogue 177Lu-DOTA-tyr3 Octreotate in Patients with Endocrine Gastoentoeropancreatic Tumors, J Clin Oncol 23:2754-2762, (2005); van Essen, M. Krenning EP, et al., Peptide Receptor Radionuclide Therapy With ¹⁷⁷ Lu-Octreotate in Patients With Foregut Carcinoid Tumors of Bronchial, Gastric and Thymic Origin, European Jnl. of Nuclear Medicine and Molecular Imaging (2007), the entire contents of which are incorporated herein by reference. In a composition comprising a molecule of formula (I) or a pharmaceutically acceptable salt thereof, at least one of ^{R 5} , R ⁶ and R ⁸ _{is (C 1} -C ₆ )alkyl-C(=O)-N(-R ²⁵ )-R ²⁶ , which may provide, for example, increased coordination stability and increased radiochemical stability properties when used in conjunction with certain radioisotopes and targeting moieties.

A radioisotope can be used to provide a source of alpha radiation, for example through indirect emission. A radioisotope (eg, ²¹² Pb, ²⁰³ Pb, ⁶⁴ Cu, etc.) is combined with a chelator (eg, DOTAM, TCMC, etc.) and a targeting moiety (eg, octreotate) to form cancer cells can provide a cancer targeting composition for rapid absorption of the composition. DOTAM and TCMC chelators can be used to avoid dissociation of radioisotopes from the conjugate under mildly acidic conditions, such as in the body of a patient.

Targeted cancer treatment may involve the use of a radioisotope bound to a chelator that binds to a targeting moiety that recognizes and binds to a cell surface receptor expressed on (or upregulated on) specific cancer cells. This can bind a radioisotope-chelator to a specific cancer cell, resulting in targeted irradiation of the specific cancer cell when the radioisotope undergoes radioactive decay.

Treatment of cancer cells (e.g., imaging and/or apoptosis) can be achieved by converting emitters (e.g., α (alpha), β (beta), γ (gamma) and/or positron emitting radioisotopes) to radioactive isotopes. may include use as (s). The α-emitting radioisotope can be delivered to targeted cancer cells, eg, NETs, via an SSTR targeting moiety, such as octreotate or other octreotide derivatives. These α-emitting radioisotopes have a high LET compared to other radioisotopes, such as ¹⁷⁷ Lu, ⁹⁰ Y and/or other β-emitters, and from about 70 to about 100 in about 1 to about 2 cancer cell clusters. They may be of particular interest as they can deposit their high energies within micrometer-long path traces. Such high LET irradiation may not depend on active cell proliferation or oxygenation, and/or the deoxyribonucleic acid (DNA) damage produced by the α-particles is due to the higher LET of the α-emitting radioisotope, Recovery may be more difficult than with β-emitting radioisotopes.

The α-emitting radioisotope can have a strong LET that is normally confined within the inner region of the cancer cell. Emission from an α-emitting radioisotope may also have the ability to cause irreversible damage to cancer cells, such as oxygenation or regeneration, without having to wait for the cancer cell's life cycle. Still further, α-emitting radioisotopes can cause apoptosis and death of cancer cells that have become resistant to β-emitter therapy.

The α-emitting radioisotope can be produced, for example, during the decay of a lead-based radioisotope, such as the ^{212 Pb radioisotope. 212} Pb is a β-emitting radioisotope with a half-life of about 10.6 hours and has a radioactive emission profile with decay products that are α-emitters with properties of an α-emitting radioisotope. ^{Since 212} Pb ^{decays to 212} Bi (which is an α-emitting radioisotope with a half-life of about 60 minutes), it decays to ²⁰⁸ Tl (with a half-life of about 3 minutes) by α-release to β-release. It ^{decays to 208} Pb (stable) by β-release, or to ²¹² Po (with a half-life of about 0.3 μs) ^{by β-release to 208} Pb by α-release.

The use of a radioisotope with a relatively empty half-life, such as ²¹² Pb, which has a half-life of about 10.6 hours, allows for the one-way production of radiolabeled compositions in radiopharmaceuticals and transport to clinics where they are administered to patients. ^The a-emitter decay of 212 Bi is maximized to occur within the cancer cell, thereby providing maximum alpha radiation damage inside the cancer cell, and apoptosis and death of the cancer cell. After α-emission by ^{212 Bi, the stable 208} Pb is ultimately produced.

As shown in the experimental data provided herein, combinations of specific radioisotopes chelated using DOTAM or TCMC conjugated to an octreotide derivative somatostatin receptor targeting moiety have therapeutic properties, such as increased radiochemical stability, cancer cells. provide improved binding to and thereby increased uptake, and/or high LET release within cancer cells, resulting in their apoptosis and/or targeted biodistribution. For example, radiolabeled-octreotate, octreotide conjugates are SSTR-targeting peptides modified with chelators (e.g., TCMC, DOTAM) that are radiolabeled with β- or α-emitting radioisotopes. can be composed of

composition

1A and 1B schematically depict exemplary cancer targeting compositions 100, 100' for treating cancer cells in a cancer patient. As shown in the example of FIG. 1A , composition 100 includes a radioisotope 102 , a chelator 104 , and a targeting moiety 108 .

The radioisotope (or radioactive atom or ion) 102 is an atom or ion, such as an α-emitter, β-emitter, γ-emitter, positron emitter, and/or capable of causing radioactive decay in a patient. It may be another radiation emitter. Radioisotope 102 can be, for example, a radiation emitter, such as ²¹² Pb, ²⁰³ Pb, ⁶⁴ Cu, ⁶⁷ Cu, ²¹² Bi, and/or other emitters of radiation. Non-limiting examples of radiation emitters that can be used as radioisotopes include ⁶⁸ Ga, ¹⁷⁷ Lu, ²¹³ Bi, and ⁹⁰ Y. Other exemplary radioisotopes that may be used include ²²⁵ Ac, ²³¹ Am, ²⁴³ Am, ²¹¹ At, ²¹⁷ At, ²⁴⁷ Bk, ²⁴⁸ Cf, ²⁵⁰ Cf, ²⁵¹ Cf, ²⁴⁰ Cm, ²⁴³ Cm, ²⁴⁵ Cm, ¹⁵⁴ Dy, ²⁵² Es, ²⁵³ Es, ²⁵⁵ Es, ²⁵² Fm, ²⁵³ Fm, ²²¹ Fr, ¹⁴⁸ Gd, ¹⁷⁴ Hf, ²⁵⁸ Md, ¹⁴⁴ Nd, ²³⁷ Np, ¹⁸⁶ Os, ¹⁹⁰ Pt, ²³⁶ Pu, ²³⁸ Pu, ²¹³ Pa, ²³¹ Pa, ²²³ Ra, ²²⁴ Ra, ²¹⁹ Rn, ¹⁴⁶ Sm, ¹⁴⁷ Sm, ¹⁴⁹ Tb, ²²⁷ Th, ²²⁹ Th, ²³⁰ U and/or ²³⁶ U may be included. Other possible radionuclides include ⁴⁵ Ti, ⁵⁹ Fe, ⁶⁰ Cu, ⁶¹ Cu, ⁶² Cu, ⁶⁷ Ga, ⁸⁹ Sr, ⁸⁶ Y, ⁹⁴ mTc, ⁹⁹ mTc, ¹¹¹ In, ¹⁴⁹ Pm, ¹⁵³ Gd, ¹⁵³ Sm, ¹⁶⁶ Ho, ¹⁸⁶ Re, ¹⁸⁸ Re or ²¹¹ At may be included.

A chelator [CA] 104 is a chemical (eg, an organic chemical) capable of binding to the radioisotope 102 and the targeting moiety 108 . The chelator 104 includes a ring structure 110 and multiple end groups 112 . Chelator 104 may be, for example, a tetraaza ring 110, such as DOTA (1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid), DOTAM (1,4). ,7,10-tetrakis(carbamoylmethyl)-1,4,7,10-tetraazacyclododecane), TCMC (2-(4-isothiocyanatobenzyl)-1,4,7, 10-tetraaza-1,4,7,10-tetra-(2-carbamoylmethyl)-cyclododecane), and/or other chelating agents. When bound by targeting moiety 108, chelator 104 can form a compound, such as DOTAMTATE, DOTATATE, TCMCTATE, and/or other chelating compounds.

Exemplary chemical structures of chelators 204a-h usable as chelator 104 are provided in FIGS. 2A1-2B4 . 2A1-2A4 show exemplary chelators usable with ²¹² Pb, ²⁰³ Pb and ^{212 Bi.} 2B1-2B4 show exemplary chelators usable with ⁶⁴ Cu and ^{67 Cu.}

Referring again to FIG. 1A , ring structure 110 includes multiple nitrogen atoms (N) bonded together by carbon atoms (eg, alkanes, alkenes, etc., shown as straight-connected vertices in FIG. 1A). Ring structure 110 may be, for example, a tetraaza ring comprising 4 nitrogen atoms. As shown in the example of FIG. 1A , one of the end groups 112 may be coupled to each nitrogen atom in the ring structure 110 . 1A , at least one of the end groups 112 may be replaced with a targeting moiety 108 . Each end group 112 may include one or more chemicals used for chelating. For example, the end group 112 may include an alkane, alkene, acetic acid, carboxylamine and/or other chemical that provides binding ability to the cancer targeting composition 100 .

The targeting moiety 108 is a chemical that binds to cancer cells in a patient, such as a somatostatin receptor (SSTR) targeting peptide (somatostatin analog). The targeting moiety 108 can be, for example, a peptide such as octreotate (HD-Phe-Cys-Phe-D-Trp-Lys-Thr-Cys-Thr-OH, C ₄₉ H ₆₄ N ₁₀ O ₁₁ S ₂ ). , Octreotide (H ₂ ND-Phe-Cys-Phe-D-Trp-Lys-Thr-Cys-Thr-ol, C ₄₉ H ₆₆ N ₁₀ O ₁₀ S ₂ ), other octreotate/octreotide derivatives , and/or other cancer targeting chemicals.

The targeting moiety 108 may be linked to the chelating agent 104 by a covalent bond 114 . A covalent bond may be coupled to an amide group, as schematically shown by a solid bond 114 , or to another portion of a tetraaza ring structure 110 , as schematically shown by a dotted bond 114 ′, such as can be coupled to carbon.

A linker [L]x (116) may also optionally be provided to bind the chelator (104) to the targeting moiety (108). Linker 116 can be, for example, an organic compound such as an amino acid, an alkane, an alkyne, or the like. The linker may be selected from the group of amino acids, peptides, amino alcohols, polyethylene glycols, alkanes, alkenes, alkynes, azide aromatics, carbohydrates, carboxylic acids, esters, phosphorus-organic compounds, and sulfonates. Linker 116 may be defined, for example, as providing a spacer between chelator 104 and targeting moiety 108 to avoid ionic interactions.

1B depicts another exemplary structure of a cancer targeting composition 100'. The cancer targeting composition 100 ′ may be similar to the composition 100 of FIG. 1A except that it has various additionally defined end groups. Radioisotope 102' (generally referred to as M) may be α, β+, β-, γ-emitting and/or other radioisotopes similar to radioisotope 102 of FIG. 1A . The chelator 104' can be a ring structure 110' having multiple nitrogen atoms bonded together, similar to the chelator 104 of FIG. 1A.

In this configuration, the end group 112' and the targeting moiety 108 are both ^shown to be R 2 and an oxygen atom bonded to each nitrogen atom of the ring structure 110'. As shown in the legend of FIG. 1B , R ² has several possible definitions, such as OH, NH, NC ₁ -C ₆ alkyl (straight or branched chain), polyethylene glycol, _{N in combination with L 1} , or of FIGS. 3A and 3B. may be N in combination with a functional group (304a, b).

Functional group 304a in FIG. 3A is further defined as comprising O in combination ^{with R 4 .} R ⁴ can be H, straight chain C ₁ -C ₆ alkyl, or branched chain C ₁ -C ₆ alkyl. Functional group 304b in FIG. 3B is further defined to include an O double bonded to C ^{with R 4 single bonded to N.}

Referring again to FIG. 1B , the targeting moiety 108 ′ is shown connected to the ring structure 110 ′ by a linker 116 ′. As shown in the legend, linker 116' is depicted as a linker ([L]x-[CA]) bound to ^{R 2 , such as a chelator.} The chelator [CA] may be similar to the chelators 104, 204a-h (or other chelators described herein) of Figures 1A, 2A1-2B4. Linker 116 ′ may be similar to linker 116 of FIG. 1A (or other linkers described herein).

As shown in Figure 4A, linker 116' is a linker coupled between _{targeting moiety 116' (shown as CO 2} H) and ring structure 110' (shown as H _{2 N).} [L]x (416a), such as oxygen (O). As shown in FIG. 4B , linker 116' is directly between linker 416b, such as a targeting moiety 116' (shown as CO ₂ H) and a ring structure 110' (H ₂ N). It may be a combination.

Although FIGS. 1A-4B depict specific configurations of cancer targeting compositions, various positions and combinations of targeting moieties, chelators and/or other components may be provided. For example, the targeting moiety may be at various positions relative to the chelator, and one or more of the various end groups may be provided. Other variations may also be provided. See, for example, US Patents/Application Nos. 2016/0143926, 2014/0228551 and 9408928, which are already incorporated herein by reference.

5A and 5B depict exemplary chemical structures (500a, 500b) for cancer targeting compositions (eg, 100, 100'). Each of the chemical structures (500a,b) comprises a chelator [CA] (504) and a targeting moiety (508a,b) and a linker ([L]x) (516). Chelator 504 and linker 516 may be similar to chelators 104, 104' and linkers 116, 116' ([L]x-[CA]) described in FIGS. 1A and 1B, respectively.

In these forms, targeting moieties 508a,b comprise TOC and TATE, respectively. DOTATOC (or dothreotide, SMT487, DOTA0-Phe1-Tyr3 octreotide or DOTA-Tyr3-octreotide) has the formula C ₆₅ H ₉₂ N ₁₄ O ₁₈ S ₂ . DOTATATE (or DOTA-TATE or DOTA-octreotate or DOTA-(Tyr ³ )-octreotate) is the amide of the acid DOTA, which acts as a chelator and has the formula C ₆₅ H ₉₀ N ₁₄ O ₁₉ S ₂ . TCMCTATE (described further herein) is of the formula S-2-(4-isothiocyanatobenzyl)-1,4,7,10-tetraaza-1,4,7,10 = tetra(2-carr bamoylmethyl) chelator with cyclododecane.

DOTAMTOC, DOTAMTATE and TCMCTATE can be synthesized as further described herein.

6A-6C depict additional chemical structures (600a-c), such as DOTATATE, DOTAMTATE and TCMCTATE, for cancer targeting compositions (eg, 100, 100'), respectively. Each of these cancer targeting compositions (600a-c) comprises a Pb radioisotope (602, 602'), a tetraaza ring (610), a chelator (604, 604', 604"), a terminal group (612, 612', 612). "), and an octreotate targeting moiety (608).

In the DOTATATE cancer targeting composition 600a of FIG. 6A , the radioisotope (M) 602 is ²¹² Pb and the end group 612 is methylenecarboxylic acid. Chelator 604 includes a tetraaza ring 610 having four (4) nitrogen atoms. Each nitrogen atom is coupled to an ethane group to form a tetraaza ring (610). The three end groups (612) are coupled to the tetraaza ring (610). Each end group 612 includes a methylcarboxyl group and is attached to one of the nitrogen atoms of the tetraaza ring. The remaining nitrogen atoms of the tetraaza ring (610) are bound to the octreotate targeting moiety (608) by a bond (614).

In the DOTAMTATE form of Figure 6B, the chelator (604') is DOTAM, the terminal group (612) is replaced by the terminal group (612'), and the radioisotope (M) (602) is the radioisotope (602'). Composition 600b is similar to that of FIG. 6A except that it is replaced by . The terminal group (612') comprises an acetamide group and the radioisotope (602') comprises ²⁰³ Pb.

In the TCMCTATE form of Figure 6C, the composition ( 600c) is similar to that of 6B. Linker 616 is linked to chelator 604' by bond 614'. In this case, end group 612" is H ₂ N.

6A-6C depict specific examples of cancer targeting compositions, it will be understood that various radioisotopes, chelators, targeting moieties, linkers and/or other components may be provided. Examples of ingredients are provided in US Patent Application Nos. US2009/0087377, US2014228551, US20120052008 and US20100316566, the entire contents of which are incorporated herein by reference. Combinations of components may be selected to achieve desired cancer targeting properties as further described herein. For example, various chelators can be used in combination with lead radioisotopes. TCMCTATE DOTAMTATE and changes the overall charge of the molecule in the case of may have a similar molecular weight and ^{DOTATATE, 203 Pb-DOTATATE (-1} ) in the case of the charge to ^{Pb-203 Pb-203} and TCMCTATE DOTAMTATE (+2) charge. In another example, although the DOTATATE, DOTAMTATE and TCMCTATE compositions of FIGS. 6A-6C are shown conjugated to octreotate, the targeting moiety can be any peptide or other targeting group capable of binding to a cancer cell.

Example

Peptide Synthesis:

Examples herein may include peptide synthesis. Cyclic peptides can be synthesized via solid phase peptide synthesis using, for example, a fluorenylmethyloxycarbonyl (FMOC) strategy. After cleavage from the solid support, disulfide bond formation can be achieved by peroxide in tetrahydrofuran (THF) and 5 mM ammonium acetate buffer (NH _{4 OAc).} The final product can be purified preparatively, such as by liquid chromatography-mass spectrometry (LC-MS or HPLC-MS). Examples of syntheses that can be used are described in Schottelius et al., HJ Wester Tetrahedron Letters vol. 44, pp. 2393-2396 (2003), the entire contents of which are incorporated herein by reference.

1,4,7,10-tetraazacyclododecane-1,4,7(2-carbamoylmethyl)-10(mono-N-hydroxysuccinimide ester [DOTAM-monocarboxylic acid] is can be synthesized by:

1. Dissolve 1,4,7,10-tetraazacyclododecane-1,4,7-tris(t-butoxycarbonyl) in acetonitrile. Add potassium carbonate. Benzyl bromoacetate is added neat. The solution is stirred at room temperature. After 4 days, the solids are removed by filtration. The solvent is removed by rotary evaporation at 40°C. The residue is dissolved in dichloromethane and washed with water. The organic layer is dried over sodium sulfate. The desiccant is removed by filtration. The solvent is removed from the filtrate by rotary evaporation. The resulting solid is dried under high vacuum to obtain the product.

2. Dissolve the isolated product from step 1 in pure trifluoroacetic acid (TFA). The solution is stirred for 1 day. TFA is removed by rotary evaporation. The resulting oil is dissolved in water and washed with chloroform. The aqueous layer is basified to pH=11 with sodium hydroxide. The product is extracted with chloroform. The organic layer is dried with sodium sulfate. Filter the solution. The solvent is removed by rotary evaporation. The residue is dried under high vacuum to give the product as an oil.

3. Dissolve the isolated product from step 2 in ethanol and add diisopropylethylamine. Then 2-bromoacetamide in ethanol is added and the solution is stirred for ≧4 hours. The solvent is removed by rotary evaporation at 35°C. The oil residue is dissolved in chloroform and any solid formed is filtered off and discarded. The solvent is removed from the filtrate by rotary evaporation. The residue is dried under high vacuum for ≧2 hours. The residue is dissolved in acetone. The solid is precipitated. The solid is filtered off and washed with cold acetone. The solid is dried under high vacuum to obtain the product.

4. The product isolated from step 3 is hydrogenated in water in the presence of 10% Pd (palladium) on activated carbon under a hydrogen pressure of 30 psi (207 kPa). The solution is filtered and the solvent is removed by rotary evaporation. The residue is dissolved in ethanol and stirred vigorously. The product is precipitated. It is filtered and dried under high vacuum.

TCMCTATE can be synthesized by: TATE is synthesized by solid phase peptide synthesis (SPPS) and cleaved from the resin without removing the protecting group of its side chain. The TATE is then dissolved in acetonitrile with diisopropylethylamine (2x molar excess). A solution of TCMC (macrocyclic product B-1005) is added and the reaction mixture is stirred at room temperature. The reaction progress is monitored by liquid chromatography-mass spectrometry (LC/MS). After completion, the solution is concentrated in vacuo. The protecting groups of the side chains are removed by a cocktail of trifluoroacetic acid and a radical scavenger, then the product is precipitated with diethyl ether. The linear peptide is cyclized in solution and the crude product is purified by preparative reverse phase liquid chromatography (RP/LC).

DOTAMTATE can be synthesized by: TATE is synthesized by SPPS and DOTAM-monocarboxylic acid (macrocyclic product B-170) is attached to the peptide while still in the resin. The peptide conjugate is cleaved from the resin by a cocktail of trifluoroacetic acid (TFA) and a radical scavenger and the product is precipitated with diethyl ether. The linear peptide is cyclized in solution and the crude product is purified by preparative reverse phase liquid chromatography (RP/LC).

DOTAMTOC can be synthesized by: TOC is synthesized by SPPS and DOTAM-monocarboxylic acid (macrocyclic product B-170) is attached to the peptide while still in the resin. The peptide conjugate is cleaved from the resin by a cocktail of trifluoroacetic acid (TFA) and a radical scavenger and the product is precipitated with diethyl ether. The linear peptide is cyclized in solution and the crude product is purified by preparative reverse phase liquid chromatography (RP/LC).

TCMCTOC can be synthesized by: TOC is synthesized by solid phase peptide synthesis (SPPS) and cleaved from the resin without removing the protecting group of its side chain. The TOC is then dissolved in acetonitrile with diisopropylethylamine (2x molar excess). A solution of TCMC (macrocyclic product B-1005) is added and the reaction mixture is stirred at room temperature. The reaction progress is monitored by liquid chromatography-mass spectrometry (LC/MS). After completion, the solution is concentrated in vacuo. The protecting groups of the side chains are removed by a cocktail of trifluoroacetic acid and a radical scavenger, then the product is precipitated with diethyl ether. The linear peptide is cyclized in solution and the crude product is purified by preparative reverse phase liquid chromatography (RP/LC). 7A-20E depict experimental data obtained using various compounds, such as the cancer targeting compositions 600a-c of FIGS. 6A-6C. As shown by these experiments, the therapeutic efficacy of cancer targeting compositions can be improved by the use of a radioisotope (eg, lead) chelated by a tetraaza ring conjugated to an octreotate targeting moiety. The results of these experiments provided a basis for the selection of DOTAMTATE or TCMCTATE octreotate conjugates for targeted cancer therapy using ^{212 Pb.}

Experiment 1 - Binding of radioisotopes to chelators

7A-8B demonstrate the stability ^{of the 203} Pb radioisotope for the compositions of FIGS. 6B and 6C. As shown in the graphs of Figures 7A-8B, both ²⁰³ Pb DOTAMTATE and ²⁰³ Pb-TCMCTATE are synthesized in high radiochemical yields. These compositions exhibit high chemical and radiochemical stability during incubation in PBS buffer at room temperature as tested at different time points over time.

In particular, FIGS. 7A-7C show radio-high performance liquid chromatography (radio-HPLC) chromatograms 700a-c. These graphs (700a-c) show ²⁰³ Pb-DOTAMTATE (15 μCi) (555 kBq) obtained at 0 h, 1 h and 24 h, respectively, after labeling ^{DOTAMTATE with 203 Pb.} Each graph 700a-c plots the radiation intensity (y-axis, mV measured by the detector) versus run time (x-axis, minutes) of radio-HPLC (high performance liquid chromatography).

These graphs also demonstrate post-labeling to determine the radiochemical yield and radiochemical stability of the agent. ²⁰³ Pb-DOTAMTATE is synthesized in a radiochemical yield of 99.9% or more. The peaks in all three chromatographs (700a-c) indicate high radiochemical stability to ^{203 Pb-DOTAMTATE.} In particular, ^{since there is no secondary peak indicative of free 203} Pb, the chromatograph shows a radiochemical yield of ≧98% after at least 24 hours of labeling. As evidenced by these graphs, ²⁰³ Pb DOTAMTATE remains radiochemically and chemically stable over time during testing.

Figure 8A and 8B illustrate a chromatograms radioactive -HPLC the ²⁰³ Pb-TCMCTATE (555 kBq or 15 μCi) obtained the TCMCTATE a second 0 hours and 18 hours, respectively, after labeling with ²⁰³ Pb (800a, b). As evidenced by these graphs, ²⁰³ Pb-TCMCTATE also remains stable over time during testing. Data after labeling are also obtained ^{to determine the radiochemical yield and radiochemical stability of 203} Pb-TCMC-TATE, which is synthesized in a radiochemical yield of > 99.9%. As shown in FIG. 8B , ²⁰³ Pb-TCMCTATE exhibits high radiochemical stability (eg, about ≧96%) up to 18 hours after labeling.

The experiments in Figures 7A-8B show the high binding affinity of DOTAMTATE and TCMCTATE to ^{203 Pb.} These figures also show that upon binding, the ²⁰³ Pb radioisotope remains bound for at least several hours.

Experiment 2 - Radioisotope Absorption

9-11 show test results demonstrating the SSTR targeting properties of radioisotopically labeled DOTAMTATE and TCMCTATE. 9 depicts ^{absorption studies for 203} Pb DOTAMTATE and TCMCTATE ^{compared to 64} Cu DOTAMTATE and TCMCTATE. 9 is a bar graph 900 depicting initial dose percentages per milligram (% ID/mg) (y-axis) for various chelators (x-axis). ^{In particular, cell uptake studies were conducted with 203} Pb-labeled AR42J cancer cell line (100,000 cells/well) incubated for 1.5 hours at 37°C in ATCC®-formulated F-12K medium containing 20% fetal bovine serum (FBS). and ⁶⁴ Cu-labeled DOTAMTATE and TCMCTATE (10 μg of isotopically labeled agent of 37 MBq (1 mCi); 888 kBq (24 μCi)/well). A DOTA chelator (eg, DOTA without a targeting moiety or radioisotope) serves as a negative control in this study.

The TCMCTATE and DOTAMTATE chelators show stable chelation of both the ²⁰³ Pb and ^{64 Cu isotopes.} Graph 900 shows ^{that the SSTR-selectivity of both 203} Pb-labeled and ⁶⁴ Cu-labeled TCMCTATE and DOTAMTATE conjugates is specific for the AR42J cancer cell line (expressing SSTR). ⁶⁴ Cu-conjugates show ^{similar uptake and accumulation rates as 203} Pb-conjugates in AR42J cell line and similar selectivity for SSTR in AR42J cell line. ^{The in vitro accumulation of 203} Pb-DOTAMTATE and ²⁰³ Pb-TCMCTATE in AR42J cancer cell line is 21.4 ± 2.26 % ID/mg and 33.41 ± 0.49 % ID/mg, respectively. A similar trend in the accumulation of both of these ^{was observed for their 64} Cu-labeled analogs, e.g., ^{the accumulation of 64} Cu-DOTAMTATE was 33.41 ± 0.49 % ID/mg and ^{the accumulation of 64} Cu-TCMCTATE was 41.59 ± 1.79 % ID/mg. is mg. This indicates that radiolabeled DOTAMTATE and TCMCTATE accumulate selectively in SSTR-expressing cancer cells.

10 depicts ^{a competition study of 203} Pb DOTAMTATE and unlabeled DOTATATE (DOTATATE without radioisotope). 10 is a graph 1000 of cellular uptake (% ID/mg) (y-axis) for various chelators (x-axis). This figure depicts an in vitro uptake and competition study performed by adding increasing amounts of unlabeled DOTATATE (5 μg/well) (DOTATATE without radioisotope) with ^{203 Pb-DOTAMTATE.} Both compositions show SSTR-specific accumulation in the cancer cells tested. ^{A competition study was conducted with 203} Pb-DOTAMTATE (17 MBq (0.46 mCi) of ²⁰³ Pb-DOTAMTATE (17 MBq (0.46 mCi)) in AR42J cancer cell line (100,000 cells/well) incubated for 2 h at 37°C in ATCC-formulated F-12K medium containing 20% FBS. 5 μg of agent labeled with Pb; 370 kBq (10 μCi)/well) and unlabeled DOTATATE (DOTATATE without radioisotope) are used. Competition studies are performed by co-incubating increasing amounts of unlabeled DOTATATE (10 μg/ml; 20 μg/ml; 50 μg/ml) with ^{203 Pb-DOTATATE.}

^{Figure 10 shows the inverse relationship between the uptake of 203} Pb-DOTAMTATE and the amount of its competitor (in this case unlabeled DOTATATE) in AR42J cancer cells when the two are co-incubated. ^{Accumulation of 203} Pb-DOTAMTATE decreased by 14%, 36%, and 65%, respectively, in the presence of increasing amounts of DOTATATE (10 μg/ml, 20 μg/ml, 50 μg/ml). This indicates that DOTAMTATE binds to the same SSTR receptor as DOTATATE.

11 depicts a ^{comparison of absorption of 203} Pb-DOTAMTATE and ²⁰³ Pb-TCMCTATE with increasing doses of these two compositions. These figures show the SSTR-targeting properties of radiolabeled-TCMCTATE and DOTAMTATE in a cell uptake study performed on SSTR-positive AR42J pancreatic cancer cells (AR42J ATCC® CRL-1492™) and in a competition study performed in the presence of unlabeled DOTATATE. indicates 11 depicts a graph 1100 depicting background corrected counts per minute (CPM) per mg cells (y-axis) for various chelators (x-axis). This figure demonstrates cellular uptake of ²⁰³ Pb-TCMCTATE and ²⁰³ Pb-DOTAMTATE in AR42J cancer cell line (100,000 cells/well). AR42J cancer cells are incubated in ATCC™-formulated F-12K medium containing 20% FBS at 37° C. for 3 hours.

²⁰³ Pb-TCMCTATE is prepared by labeling TCMCTATE (10 μg) with 37 MBq (1 mCi), 152 MBq (4.1 mCi) or 233 MBq (6.3 mCi) of ²⁰³ Pb radioisotope. ²⁰³ Pb-DOTAMTATE was prepared by labeling DOTAMTATE (5 μg) with 5.1 MBq (0.14 mCi), 21.4 MBq (0.58 mCi) or 26.6 MBq (0.72 mCi) of ²⁰³ Pb isotopes. ²⁰³ Pb-TCMC without a targeting moiety served as a negative control in these studies.

Increased accumulation of ²⁰³ Pb-TCMCTATE and ²⁰³ Pb-DOTAMTATE (measured in CPM/mg cells) in AR42J cells resulted in increasing amounts of octreotate conjugate (0.018 μg, 0029 μg for TCMCTATE and 0.12 μg, and 0.108 μg and 0.453 μg for DOTAMTATE). Bars represent values of CPM (background corrected) per mg cells. The line represents the value of CPM per mg cells per mg peptide conjugate used in the study. As can be seen from the similar slope of the lines, both ²⁰³ Pb-DOTAMTATE and ²⁰³ Pb-TCMCTATE behave in a similar manner with increasing concentration.

11 suggests a direct correlation between the accumulation of cancer targeting composition in AR42J cancer cell line and the amount of cancer targeting composition used in uptake studies. As the amount of ^{Pb-203 Pb-203} and DOTAMTATE TCMCTATE added to cancer cells increases, the increase in the absorption of the AR42J cancer cell lines both in the ^{203 Pb-203} and Pb-TCMCTATE DOTAMTATE. These results show the SSTR-targeting properties of radiolabeled DOTAMTATE and TCMCTATE. Specificity is demonstrated by saturation of the receptor as evidenced by a decrease in CPM per mg cells per mg peptide with increasing amount of peptide added.

in more detail

Biodistribution study in athymic mice bearing AR42J xenografts

Way:

Female athymic nude mice (-20 g) are injected subcutaneously with ^{2×10 6} AR42J cells in 50% RPMI medium and 50% Matrigel. The tumor is grown until the tumor volume reaches approximately 300 mm ^{3 . A dose (5 μCi) of 212} Pb-DOTAMTATE is prepared in phosphate buffered saline (PBS) and 200 μl is administered to mice via intravenous injection. Animals are sacrificed at scheduled time points 1, 4 and 24 hours after drug injection. Tissues are collected from each animal and the amount of radioactive material is assessed in each organ by an automatic gamma counter. Specifically, organs are harvested, weighed, and transferred to 12 x 55 mm polypropylene tubes. Place the tube in a calibrated Wizard2 γ-counter (PerkinElmer, Shelton, CT) and count (204 - 274 keV) for 3 minutes. A standard consisting of 1/20 of the injection volume is counted at each time point. The background is automatically subtracted from the count. This standard is also used for decay correction. Calculate % ID/g for each organ collected.

Results and Conclusions:

Tumor uptake was greater than 20% 1 hour after drug administration and remained constant over 4 to 24 hours. Other non-target organs showed the highest drug accumulation 1 hour after injection, but decreased significantly by 24 hours post-dose. Pancreas and kidney are the two organs with the highest non-target uptake, but these organs showed significantly lower accumulation by 24 hours post-injection. This observation is not of concern based on the toxicology and efficacy data we have accumulated to date. In addition, these organs also showed high drug uptake in other nonclinical rodent studies involving alpha emitters, which did not translate into negative effects in human studies (Kratochwil et al., 2014; Norenberg et al., 2006).

Experiment 3 - Biodistribution

12-13 depict biodistribution studies of cancer targeting compositions in patients. ^{12 depicts the biodistribution for 203} Pb-DOTAMTATE and ²⁰³ Pb-TCMCTATE in non-tumor bearing mice. ^{13 depicts the biodistribution of radioisotope 203} Pb-acetate without chelator or targeting moiety in non-tumor bearing mice. These figures show that the biodistribution of the chelated radioisotope is enriched in the kidney, suggesting that the radioisotope may be safer when chelated to DOTAMTATE and TCMCTATE.

12 is a bar graph 1200 depicting biodistribution (% ID/g) (y-axis) for various organs (x-axis). ^{The biodistribution of 203} Pb-TCMCTATE and ²⁰³ Pb-DOTAMTATE is shown for non-tumor bearing mice 4 hours after injection. ^{Biodistribution studies of 203} Pb-TCMCTATE and ²⁰³ Pb-DOTAMTATE are completed in non-tumor-bearing mice (CD-1 mice, females, 20 g wt. 4-5 weeks of age) 4 hours after injection of the cancer targeting composition.

^{Both 203} Pb-DOTAMTATE and ²⁰³ Pb-TCMCTATE show limited or no uptake in bone marrow, liver or other organs, thus indicating the radiochemical stability of these specific cancer targeting compositions. While the kidneys show increased accumulation of agents, retention of cancer targeting compositions in other organs is less than 2% ID/g (% of initial dose per gram of organ). Both compositions have similar pharmacokinetic properties and high radiochemical stability indicated by limited absorption/no absorption by the bone marrow, liver and lungs. In particular, the kidneys have respective 23.53 ± 1.54% ID / g and 9.79 ± 2.9% ID / g higher than that of a ²⁰³ Pb- labeled TCMCTATE ²⁰³ and Pb-DOTAMTATE pictures. High renal retention of radiolabeled DOTATATE analogs is reduced by co-administration of positively charged amino acids during peptide receptor radionuclide therapy (PRRT). This indicates that the radioisotope remains tightly bound to the chelator-targeting moiety in the body and the cancer targeting composition does not bind to non-targeted cells.

^{For comparison, FIG. 13 is a graph of FIG. 12 except that a biodistribution study of 203} Pb-acetate (lead radioisotope without a chelator or targeting moiety) was performed in non-tumor bearing mice 4 hours after injection. ) is a graph 1300 . A higher accumulation of the isotope is observed in blood, kidney, liver and lung compared to the chelated radioisotope of FIG. 12 . ^{Biodistribution studies of 203} Pb-acetate show isotope retention in bone marrow, blood and liver 4 hours after injection.

As can be seen by comparing FIGS. 12 and 13 , ^{the long-term distribution of 203} Pb-DOTAMTATE and ²⁰³ Pb-TCMCTATE ( FIG. 12 ) is ^{different from that observed for the free 203} Pb isotope ( FIG. 13 ), and thus This indicates the in vivo stability of lead isotopes chelated to DOTAMTATE and TCMCTATE.

14 and 15 depict the biodistribution of ²¹² Pb-DOTAMTATE in two different strains of AR42-J tumor bearing mice. These figures show some differences in the organ distribution of the compositions in different strains of mice tested.

14 is a bar graph 1400 depicting the biodistribution results (% ID/g) (y-axis) of a composition in various organs (x-axis) as a function of time. The graph shows the biodistribution results (bars) of ²¹² Pb-DOTAMTATE obtained at different time points (1 h, 4 h and 24 h) after injection in tumor bearing mice (AR42J tumor model).

Similarly, FIG. 15 is a bar graph 1500 depicting the biodistribution results (% ID/g) (y-axis) of a composition in various organs (x-axis). Figure 15 shows the biodistribution results (bars) of ²¹² Pb-DOTAM-TATE in the CB17-SCID strain of AR42J mice performed 4 and 24 hours after injection. This experiment is similar to the experiment of FIG. 14 , except that the composition of FIG. 15 was administered to tumor-bearing mice also with severe combined immune deficiency (SCID).

As can be seen from Figures 14 and 15, composition ²¹² Pb-DOTAM-TATE accumulates in SSTR-expressing tumors and in normal organs known to have higher expression of SSTR, such as the pancreas. The composition is cleared through the bladder and kidneys, which contributes to higher retention of the agent in these organs. Although there is variation in the biodistribution of the composition between strains of AR42J mice as shown in FIGS. 14 and 15 , in both cases there is accumulation and retention of the composition in the tumor over time. This indicates that the composition can be localized in SSTR-expressing tumors despite differences in the subject's strain (such as severe combined immunodeficiency (SCID)).

^{16 depicts the results of 203} Pb-DOTAMTATE biodistribution in non-tumor bearing athymic nude mice over time. 16 is a bar graph 1600 showing the biodistribution results (% ID/g) of ²⁰³ Pb-DOTAMTATE in various organs (y-axis). Biodistribution data are acquired 4 hours, 24 hours and 48 hours post injection. 16 shows that ²⁰³ Pb-DOTAMTATE initially accumulates in SSTR-expressing organs, such as the pancreas and stomach of non-tumor bearing athymic nude mice. Accumulation of the composition in the kidneys and bladder is also observed due to clearance of the composition through renal clearance. As can be seen from these figures, the composition is washed out of all measured organs over time in non-tumor bearing mice.

in more detail

²⁰³ PB-DOTAMTATE biodistribution in athymic nude mice

²⁰³ Pb-DOTAMTATE has been tested by our group in both animal and human models, and ^{the use of 203} Pb-DOTAMTATE as a surrogate for ²¹² Pb-DOTAMTATE is the subject of a recent eIND (130,960).

Way:

Inject female athymic nude mice (~20 g) with a single dose of ²⁰³ Pb-DOTAMTATE. Specifically, 10 μCi of ²⁰³ Pb-DOTAMTATE is diluted in PBS, and 100 μl is administered to mice via intravenous injection. Animals are sacrificed at scheduled time points 4, 24 and 48 hours after drug injection. Tissues are collected from each animal and the amount of radioactive material is assessed in each organ by an automatic gamma counter. Specifically, organs are harvested, weighed, and transferred to polypropylene tubes. Place the tube in a calibrated Wizard2 γ-counter (PerkinElmer, Shelton, CT) and count (204 - 274 keV) for 3 minutes. A standard consisting of 1/20 of the injection volume is counted at each time point. The background is automatically subtracted from the count. This standard is also used for decay correction. Calculate % ID/g for each organ collected.

Results and Conclusions:

Referring to Figure 16, long-term absorption in athymic nude mice treated with ^{203 Pb-DOTAMTATE is similar to that confirmed by 212} Pb-DOTAMTATE in this mouse strain: high initial absorption of drug in pancreas and kidney, time course continues to decrease accordingly. This indicates that ²⁰³ Pb-DOTAMTATE and ²¹² Pb-DOTAMTATE act similarly as expected in that they are the same peptide and metal.

^{17 includes biodistribution of 212} Pb-DOTAM-TATE in non-tumor bearing male and female mice. 17 is a bar graph 1700 depicting the results of the biodistribution (% ID/g) (y-axis) of a composition in various organs (x-axis). ^{Biodistribution studies of 212} Pb-DOTAM-TATE are performed in both males and females in non-tumor bearing CD1 mice 4 and 24 hours after injection. Both male and female mice have a similar pattern of biodistribution, indicating that the distribution of the compound is not significantly affected by the subject's sex.

in more detail

^{Biodistribution of 212} PB-DOTAMTATE in male and female non-tumor-bearing mice

For numerous studies, an extensive literature search is performed to support small differences between male and female mice, particularly as criteria for selecting female mice for GLP toxicity studies. Additionally, the small difference observed is the higher sensitivity in female mice, which would be the worst-case scenario between the two sexes (Lipnick et al., 1995), suggesting that it is more commonly used in safety assessments (OECD, 2000). do.

⁶⁸ Several clinical studies of Ga-DOTATATE PET/CT indicate no differences in radiotracer distribution and its organ retention between male and female patients. However, ^{a recent retrospective evaluation of data from 161 patients enrolled in a clinical study of 68} Ga-DOTATATE PET/CT revealed age- and sex-related variations in radiotracer accumulation in some organs (Watts, Singh, Shukla, Sharma). , & Mittal, 2014). Female patients (n=31) demonstrated higher normalized absorption values (SUVs) in the pituitary, thyroid, parotid, spleen and kidney compared to males (n=34) (p<0.05).

^{Renal radioactivity in female rats injected with 111} In-DTPA-octreotide showed different localized patterns. Female rats exhibited higher uptake in the external medulla compared to the cortex (Melis et al., 2007).

Renal retention of radiotherapeutic agents can lead to nephrotoxicity and renal failure. Selection of female mice for toxicity studies allows to determine the effect of ²¹² Pb-DOTAMTATE on renal function, especially when higher retention of the agonist is expected in females.

To better elucidate how this particular radiotherapeutic agent, ²¹² Pb-DOTAMTATE, is similar between male and female mice, we performed biodistribution at two scheduled time points in CD-1 non-tumor bearing mice.

Way:

Male and female CD-1 mice (~20 g) ^{are injected with a single dose of 212} Pb-DOTAMTATE. Specifically, 5 μCi of ²¹² Pb-DOTAMTATE is diluted in PBS, and 100 μl is administered to mice via intravenous injection. Animals are sacrificed at scheduled time points 4 and 24 hours after drug injection. Tissues are collected from each animal and the amount of radioactive material is assessed in each organ by an automatic gamma counter. Specifically, organs are harvested, weighed, and transferred to polypropylene tubes. Place the tube in a calibrated Wizard2 γ-counter (PerkinElmer, Shelton, CT) and count (204 - 274 keV) for 3 minutes. A standard consisting of 1/20 of the injection volume is counted at each time point. The background is automatically subtracted from the count. This standard is also used for decay correction. Calculate % ID/g for each organ collected.

Results and Conclusions:

Referring to Figures 17A and B, there is no significant difference in the long-term uptake ^{of 212 Pb-DOTAMTATE between male and female mice.} There are some observable differences, which can be explained by the greater mass of the males. Male and female mice had similar drug absorption in all organs at both 4 and 24 hours post-injection. This slightly higher % ID/g and thus absorbed dose in female mice further supports their use in toxicology studies.

Experiment 4 - Efficacy

18, 19A-B and 20A-20E are experiments demonstrating the therapeutic efficacy of ^{different doses of 212 Pb-DOTAMTATE administered in AR42J-tumor bearing mice.} 18 depicts a graphical 1800 survival curve of AR42J-tumor bearing mice over time post injection after administration of increasing doses of the composition. Graph 1800 plots survival (% survival) (y-axis) of (week) (x-axis) tumor-bearing mice over time as a function of ^{212 Pb-DOTAMTATE dose.} 18 shows survival for AR42J mice injected with ²¹² Pb-DOTAMTATE at 185 kBq (5 μCi), 2x185 kBq (2x5 μCi), 370 kBq (10 μCi), 2x370 kBq (2x10 μCi) or 3x370 kBq (3×10 μCi). show the curve. In addition, two control groups of mice receiving PBS (phosphate buffered saline) alone or non-radiolabeled cryo-DOTAMTATE are used. The percentage of surviving mice in each of these groups is determined as a function of time. The graph shows that increasing doses of ²¹² Pb-DOTAMTATE correlate with increased survival in mice. All groups of mice that received the composition had a higher survival rate compared to that of the control group.

19A-B and 20A-E depict changes in tumor volume of individual mice in treated groups as a function of time and injection dose. 19A-20E show ^{the change in tumor volume (mm 3} ) (y-axis) over time (x-axis) for individual mice in each tested group after administration ^{of different doses of 212 Pb-DOTAMTATE.} It is a graph (1900a-2000e) shown. 19A-19B depict graphs (1900a-1900b) depicting PBS and cold-DOTAMTATE used as negative controls, respectively, similar to the control of FIG. 18 .

20A-20E show a single dose of 185 kBq (5 μCi) (20A), two doses of 185 kBq (2×5 μCi) (20B), a single dose of 370 kBq (10 μCi) (20C), two doses, respectively. Tumor volume measured in each tumor-bearing AR42J mouse injected with a dose of 370 kBq (2 x 10 μCi) (20D), and three doses of 370 kBq of ^{212 Pb-DOTAMTATE (3 x 10 μCi) (20E).} Graphs (2000a-e) of the effect of a dose of ^{212 Pb-DOTAMTATE on} Similar to the data in Figure 18, Figures 20A-20E show that increasing doses of ²¹² Pb-DOTAMTATE correlate with decreased tumor volume over time.

19A-19B and 20A-20E show that the composition may be effective in therapy of SSTR-expressing tumors. These experiments show that increasing doses of ²¹² Pb-DOTAMTATE correlate with both increased survival and decreased tumor volume over time.

Based on in vitro uptake results in AR42J cells, competition studies with DOTATATE, and similar biodistribution profiles of DOTATATE, DOTAMTATE and TCMCTATE, such as similar renal clearance, DOTAMTATE and TCMCTATE have further investigation in exploratory clinical studies of cancer-targeting compositions. can be considered for

Although the experiments provided herein employ specific radioisotopes, the present disclosure is intended to apply to compositions, such as various other radioisotopes. For example, LET of α-emitting radioisotopes causes them to irradiate an area approximately the size of cancer cells or small clusters of cancer cells. This indicates that little to no excess radiation may be emitted beyond the targeted cancer cell(s). In comparison, other radioactive emissions can travel long distances in the body and damage non-targeted cells.

Additionally, since the data herein indicate the ability of chelators, such as DOTAM, to coordinate lead radioisotopes, radioisotope substitutions may be considered insignificant. As discussed herein, DOTAM and TCMC exhibit limited to no dissociation of lead radioisotopes compared to other chelators such as DOTA. Additionally, this indicates that the stability of the radioisotope coordination by these chelators can be extrapolated to the binding of the chelator to the radioisotope.

21 is a schematic diagram of a cancer treatment kit 2100 and methods associated with making and/or using the same. Kit 2100 comprises a chelator 104 and a targeting moiety 108 (eg, DOTAMTATE, TCMCTATE, etc.), and a radioisotope 102 (eg, ²⁰³ Pb, ²¹² Pb, etc.) compositions, such as those described herein (see, eg, FIGS. 5A-6C ). The composition can be mixed with a buffer 1124 (eg, ammonium acetate, etc.). The mixture may include, for example, 25-50 μg of the cancer targeting composition and 0.4M ammonium acetate.

The kit may also contain optional scavengers (eg, diethylenetriamino-pentaacetic acid (DTPA), ethylene diamine tetraacetic acid (EDTA), DOTA, etc.) (1126) and/or antioxidants (1128) (eg, , ascorbic acid, gentisic acid, ethanol, vitamin C, etc.). Various additives may be optionally provided as needed for various applications. As also shown in the scheme, the composition may be administered alone or in combination with other ingredients and administered to a patient.

The method may also include optional mixing and/or heating. The heating temperature and duration may vary based on the components of the kit. For example, if the chelator is DOTAM, the mixture can be heated to room temperature for 15 minutes. In another example, when the chelator is DOTA, the mixture can be heated to 85° C. for 15 minutes.

Kits can be used, for example, for the manufacture of radiopharmaceutical preparations. The kit may include a sealed vial or bag, or any other type of suitable container, containing a predetermined amount of the composition. The components of the kit may be in any suitable form, such as liquid, frozen, dried and/or lyophilized form.

22 is a flow diagram depicting a method 2200 of targeted radiotherapy of cancer cells. The method comprises providing (eg, mixing) a cancer targeting composition comprising 2230 - a radioisotope, a chelator and a targeting moiety. The chelator comprises a nitrogen ring structure, and the nitrogen ring structure comprises a derivative selected from the group of tetraazacyclododecane derivatives, triazacyclononane derivatives, and tetraazabicyclo[6.6.2] hexadecane derivatives. The targeting moiety includes a somatostatin receptor targeting peptide. Somatostatin receptor targeting peptides include octreotide derivatives. The targeting moiety is chelated to the radioisotope by a chelator. The targeting composition can be any of those described herein. See, for example, FIGS. 6B and 6C.

The method comprises 2232 - administering a cancer targeting composition to a patient having cancer cells, 2234 - binding a targeting moiety to the cancer cells, 2236 - uptake of the cancer targeting composition into the cancer cells, and 2238 - release of beta particles. disrupting the radioisotope, and removing the 2242 - cancer targeting composition from the patient. The decay 2238 may include a decay of ²¹² Pb to ^{212 Bi by the release of a beta particle and a decay of 212} Bi to ²⁰⁸ Ti by the release of an alpha particle, wherein the decay occurs within the cancer cell and/or 2240 - Cancer cells are killed by alpha particles.

in more detail

Efficacy study in athymic nude mice bearing AR42J xenografts treated with ^{212 PB-DOTAMTATE}

Way:

2 million (2x10 ⁶ ) AR42J cells are implanted subcutaneously in the right flank of each mouse, and tumors are allowed to grow until reaching an approximate tumor volume of ^{300 mm 3 .} Animals are then injected with 100 μl of 5 μCi or 10 μCi of ²¹² Pb-DOTAMTATE, cold DOTAMTATE or PBS. Animals are monitored daily and tumor volume is monitored by calipering three times a week. Tumor volume ^{reached 2000 mm 3} or met other scheduled termination criteria (weight loss >15% for 2 consecutive days, severe bleeding, tumor necrosis or ulceration, messiness or lack of grooming for >5 days, 3 Lethargy for more than one day, weakness/balance problems for more than five days, hunchback appearance, diarrhea or hypothermia) Mice are sacrificed.

After 3 weeks, two-thirds of the remaining animals from the ²¹² Pb-DOTAMTATE 10 μCi or ²¹² Pb-DOTAMTATE 5 μCi groups receive a second injection ^{of 212 Pb-DOTAMTATE at 10 μCi or 5 μCi, respectively.} Monitor these mice as described above and collect tumor volume data. Animals are maintained until tumor volume reaches 2000 mm ³ or meets the aforementioned termination criteria.

After 3 weeks, half of the animals remaining at ^{2 x 10 μCi 212} Pb-DOTAMTATE are injected with a third injection ^{of 10 μCi of 212 Pb-DOTAMTATE.} Monitor these mice as described above and collect tumor volume data. Animals are maintained until tumor volume reaches 2000 mm ³ or meets the aforementioned termination criteria. The study is completed 29 weeks after the first injection.

Results and Conclusions:

Animals injected with cold-DOTAMTATE had a median survival time 3.4 weeks after injection. Animals treated with PBS alone had similar median survival after 3.5 weeks of injection. Mice given a single injection of 5 μCi ²¹² Pb-DOTAMTATE had a median survival of 6.3 weeks, whereas mice given a single injection of 10 μCi ²¹² Pb-DOTAMTATE had a median survival of 8.5 weeks, which is equivalent to the dose A higher value indicates a more potent effect. Animals that received two injections of 5 μCi ²¹² Pb-DOTAMTATE had a median survival of 7.1 weeks. Median survival times are similar between animals receiving 1x10 μCi versus 2x5 μCi of drug. Mice that received two injections of 10 μCi ²¹² Pb-DOTAMTATE had a median survival of 10.9 weeks, and at the end of the study, 20% of the mice were tumor-free. Mice given the 3 x 10 μCi injection had a median survival of 11.6 weeks, and at the end of the study (6 months) 33% of the animals in this group were tumor-free. This suggests a dose-dependent efficacious effect with repeated injections at levels where a single injection could be toxic (see study NET0016). Kaplan-Meier survival curves summarize survival for each injection group.

Binding efficiency of ²¹² PB-DOTAMTATE to SSTR-expressing cells

Way:

_{Peptide binding to somatostatin receptor 2 (SSTR2) and K d} are assessed in SSTR2-expressing AR42J cells by growing 250,000 cells for 48 h in wells of 24-well plates. ²¹² Pb-DOTAMTATE at a concentration of 0.5 nM to 64 nM is incubated in AR42J containing wells at 37° C. for 10 minutes. For each concentration, it is performed in 4 sets. Cells are then washed with PBS and cells from each well are counted for the presence of radiation. Binding curves are then generated and K _d calculated.

Results and Conclusions:

Referring to FIG. 23 , a one-site total saturation binding curve was generated using GraphPad Prism, and a K _d of 12.9 nM was measured. This is consistent with what was observed for DOTATATE (Ullrich et al., 2016). Therefore, we report specific binding of ²¹² Pb-DOTAMTATE to the SSTR2 receptor on AR42J cells.

Cytotoxic effect of ²¹² PB-DOTAMTATE on SSTR-expressing cells

Way:

Thirty thousand (3x10 ⁴ ) AR42J cells are grown for 2 days in wells of 96 well plates. Cells are then incubated for 4 hours with ^{increasing doses of 212} Pb-DOTAMTATE ranging from 0 nCi/ml to 800 nCi/ml. Treat 8 wells per group. The cells are treated with PBS to remove the drug, and then fresh medium is introduced. Cells are incubated at 37° C. for 6 days. Cells are then washed, incubated with fluorescein diacetate for 30 min and read at 485/535 nm using a fluorometer. Calculate the percentage of viable cells based on untreated cells as control.

Results and Conclusions:

Referring to FIG. 24 , a dose-dependent cytotoxic effect can be confirmed by complete cell death occurring at 800 nCi/ml. 50% viability is observed between 12.5 nCi/ml and 25 nCi/ml. This suggests targeted killing of cells by peptides showing specificity for the SSTR2 receptor on AR42J cells. Negative control, cells treated with DOTAM alone showed no dose dependent effect with viability ranging from 47% to 156% compared to untreated control (data not shown). This suggests that the chelate alone does not cause a dose-dependent decrease in survival and is not specific for the SSTR2 receptor. Thus, peptides are required for proper and effective targeting and killing of cancer cells.

Correlation between AR42J tumor volume and drug uptake

Way:

Calculate AR42J tumor volume by measuring ^{½ x length x width 2} using a digital caliper on the day of drug administration in athymic nude mice from study NET001 presented. As shown in FIG. 25 , ^{a tumor volume of approximately 300 mm 3} is ideal, but there was some variation.

Results and Conclusions:

Referring to FIG. 26 , despite variations in tumor size, there is no visible correlation between tumor size and percentage of injected dose per gram. In one group, the smallest tumors had a high % ID/g compared to the larger tumors, while in another group, the smallest tumors had a low % ID/g compared to the larger tumors in that group. This suggests that tumor size variability does not translate into variability in tumor uptake.

Receptor saturation is not caused by reduced intrinsic activity in athymic nude mice

Way:

Female athymic nude mice (˜20 g) are injected subcutaneously with ^{2×10 6} AR42J cells in 50% RPMI medium and 50% Matrigel. The tumor is grown until it reaches an approximate tumor volume of 300 mm ^{3 . Doses of 212} Pb-DOTAMTATE are prepared in PBS at three different intrinsic activities (10 μCi). 200 μl is administered to mice via intravenous injection. Animals are sacrificed 24 hours after drug injection. Tissues are collected from each animal and the amount of radioactive material is assessed in each organ by an automatic gamma counter. Specifically, organs are harvested, weighed, and transferred to polypropylene tubes. Place the tube in a calibrated Wizard2 γ-counter (PerkinElmer, Shelton, CT) and count (204 - 274 keV) for 3 minutes. A standard consisting of 1/20 of the injection volume is counted at each time point. The background is automatically subtracted from the count. This standard is also used for decay correction. Calculate % ID/g for each organ collected.

Results and Conclusions:

Referring to Figure 27, three intrinsic activities were tested in a biodistribution study. To date, ^{10 μCi per 4.1 ng has been the most used in the 212} Pb-DOTAMTATE study, but the decrease in intrinsic activity does not appear to have a significant effect on tumor uptake. This suggests that receptor saturation does not occur even at over 25-fold lower intrinsic activity, which was mainly used in these studies.

Efficacy study in athymic nude mice bearing AR42J xenografts treated with ²¹² PB-DOTAMTATE with treatment cycles of 2 and 3 weeks

Way:

Two million (2x10 ⁶ ) AR42J cells are implanted subcutaneously in the right flank of each mouse and the tumors are allowed to grow until reaching an approximate tumor volume of ^{200-300 mm 3 .} Animals are then injected with 100 μl of 10 μCi ²¹² Pb-DOTAMTATE or saline. Animals are monitored daily and tumor volume is monitored by calipering three times a week. Tumor volume ^{reached 3000 mm 3} or met other scheduled termination criteria (>15% weight loss over two consecutive days or 20% weight loss from initial weight, severe bleeding, tumor necrosis or ulceration, >5 days Messy or lack of grooming, lethargy for more than 3 days, weakness/balance problems for more than 5 days, hunchback appearance, diarrhea or hypothermia) Mice are sacrificed.

After 2 or 3 weeks, animals are given a second dose of ^{10 μCi of 212 Pb-DOTAMTATE.} Monitor these mice as described above and collect tumor volume data. Animals are maintained until tumor volume reaches 3000 mm ³ or meets the aforementioned termination criteria.

After 2 or 3 weeks, animals receive 10 μCi of ²¹² Pb-DOTAMTATE. Monitor these mice as described above and collect tumor volume data. Animals are maintained until tumor volume reaches 3000 mm ³ or meets the aforementioned termination criteria. Continue your research.

Results and Conclusions:

28 AC and 29 , animals injected with saline had a median survival of 2.3 weeks after saline injection. ^{Mice given three injections of 212} Pb-DOTAMTATE had a median survival of 9.1 weeks after cell injection, with all animals lost at 11.1 weeks. ^{Animals that received three injections of 212} Pb-DOTAMTATE at 2-week intervals had a median survival of 11.9 weeks, with 45% of animals alive 21 weeks after cell injection. These data indicate that the timing of drug treatment is critical to the effect of tumor volume. Tumor volume can be controlled, but if the period between cycles is too long, the treatment is less effective.

Animal Hematological Pharmacokinetics of ^{IV-Injected 212} PB-DOTAMTATE in CD-1 Mice

Way:

As part of a biodistribution study, CD-1 mice were ^{injected with 10 μCi of 212} Pb-DOTAMTATE. 15 minutes after blood injection; Collect at 1 hour and 4 hours. The weight was obtained by averaging 10 CD-1 mice of 7 weeks of age (the age of the mice in this study), and using this weight, the blood volume was calculated by the equation of Lee and Blaufox (1985). estimate % ID is then calculated in mouse blood for 5 mice per group.

Results and Conclusions:

Referring to Figure 30 and Table 1, the mean % ID in blood is ^{6.7% 15 minutes after 212} Pb-DOTAMTATE injection, suggesting rapid clearance. One hour after injection, the % ID of blood further decreases to 1.8%. 4 hours after injection, the level of drug in the blood is almost undetectable as 0.1% ID. The data is presented in the table below and graphs are made over time.

Table 1. Mean % ID of ²¹² Pb-DOTAMTATE in the blood of CD-1 mice.

^{Biodistribution of 212} PB-DOTAMTATE in Female Non-Tumor Bearing Mice

^{The distribution of 212} Pb-DOTAMTATE is assessed in a biodistribution study by CD-1 non-tumor bearing mice at multiple time points between 15 minutes and 48 hours.

Way:

Female CD-1 mice (~20 g) ^{are injected with a single dose of 212} Pb-DOTAMTATE. Specifically, 10 μCi of ²¹² Pb-DOTAMTATE is diluted in PBS, and 100 μl is administered to mice via intravenous injection. Animals are sacrificed at scheduled time points 15 min, 1 h, 4 h and 24 h and 48 h after drug injection. Tissues are collected from each animal and the amount of radioactive material is assessed in each organ by an automatic gamma counter. Specifically, organs are harvested, weighed, and transferred to polypropylene tubes. Place the tube in a calibrated Wizard2 γ-counter (PerkinElmer, Shelton, CT) and count (204 - 274 keV) for 3 minutes. A standard consisting of 1/20 of the injection volume is counted at each time point. The background is automatically subtracted from the count. This standard is also used for decay correction. Calculate % ID/g for each organ collected.

Results and Conclusions:

Referring to FIG. 31 , all organs have an injection dose percentage per gram of less than 10% for each of the time points specified (except the kidneys). ^{The greatest accumulation of 212} Pb-DOTAMTATE occurs in the kidneys, with the highest levels observed 1 hour after injection (~30% of injected dose per gram). It significantly decreased to an injection dose per gram of nearly 10% by 24 hours after injection and continued to decrease after 48 hours. Since the kidneys are the primary method of clearance for drugs, this is not an unexpected observation and is not a state of concern based on other data, primarily the toxicology and efficacy data obtained by the inventors.

^{Biodistribution of 203} PB-DOTAMTATE and ²¹² PB-DOTAMTATE in CD-1 Non-Tumor Bearing Mice

Way:

Female CD-1 mice (~20 g) ^{are injected with a single dose of either 203} Pb-DOTAMTATE or ²¹² Pb-DOTAMTATE. Specifically, 10 μCi of ²⁰³ Pb-DOTAMTATE or ²¹² Pb-DOTAMTATE is diluted in saline, and 100 μl is administered to mice via intravenous injection. Animals are sacrificed at scheduled time points 4 and 24 hours after drug injection. Tissues are collected from each animal and the amount of radioactive material is assessed in each organ by an automatic gamma counter. Specifically, organs are harvested, weighed, and transferred to 12 x 55 mm polypropylene tubes. Place the tube in a calibrated Wizard2 γ-counter (PerkinElmer, Shelton, CT) and count (204 - 274 keV) for 3 minutes. A standard consisting of 1/20 of the injection volume is counted at each time point. The background is automatically subtracted from the count. This standard is also used for decay correction. Calculate % ID/g for each organ collected, where "% ID" means percentage of injected dose.

Results and Conclusions:

Referring to FIG. 32 , long-term absorption in CD-1 mice treated with ²⁰³ Pb-DOTAMTATE was not significantly different from that in mice treated with ^{212 Pb-DOTAMTATE in all important organs.} This direct side-by-side comparison further confirms that the two isotopes have similar pharmacokinetic profiles.

Based on these data and the like, an exploratory eIND (Exploratory Investigational New Drug) was performed, ^{and as a surrogate for 212} Pb-DOTAMTATE, in patients with somatostatin-expressing neuroendocrine cancer, ²⁰³ Pb-DOTAMTATE was Radiation dosimetry and biodistribution are evaluated. ^{The distribution and excretion characteristics of 203} Pb-DOTAMTATE are very similar to the PK (pharmacokinetic) properties of commercially available octreotate drugs, and the kidney is a dose limiting organ.

²¹² PB-DOTAMTATE Cumulative Emissions

Way:

Female CD-1 mice are ^{injected intravenously with 10 μCi of 212} Pb-DOTAMTATE. The animals are then placed in individual metabolizing cages to facilitate fecal collection. At scheduled intervals of 1 hour, 2 hours, 3 hours, 4 hours, 5 hours, 6 hours and 24 hours after injection, animals are removed from the metabolic cage and placed in a new metabolic cage. Then, our funnels are washed with PBS and 1 ml from each mouse is counted in an automatic gamma counter. Stool is collected and analyzed in a separate automated gamma counter tube.

Results and Conclusions:

Referring to FIG. 33 , ^{the results of the 212} Pb-DOTAMTATE study indicate that the drug is metabolized by the kidneys and passes through urine and feces. The level of drug found in the feces at 24 h is consistent with what would be expected given the 24 h biodistribution data performed also in CD-1 mice.

^{Biodistribution of 212} PB-DOTAMTATE by Renal Protective Agents

²¹² Pb-DOTAMTATE is not expected to interact with key molecular pharmacokinetic determinants such as enzymes, drug transporters, or orphan nuclear receptors. However, renal toxicity has been reported to be of concern with high-dose radionuclide therapy. Co-injection of drugs with positively charged amino acids has been shown to reduce the renal capacity of radiolabeled octreotide by 25% (Hammond et al., 1993). As a result, ^{renal protection studies using 212} Pb-DOTAMTATE and various agents were performed to determine if exposure to the kidneys could be minimized during treatment.

Way:

Female CD-1 mice (~20 g) ^{are injected with a single dose of 212} Pb-DOTAMTATE. Specifically, 5 μCi of ²¹² Pb-DOTAMTATE was mixed with PBS (control), 2.5% lysine-arginine mixture, aminomedics (600 mg/kg Lys-Arg, 15 mg/kg amifostine half diluted in PBS) or 4.2 % Clinisol and administered to mice via intravenous injection. Animals are sacrificed at scheduled time points 1 and 4 hours after injection. Tissues are collected from each animal and the amount of radioactive material is assessed in each organ by an automatic gamma counter. Specifically, organs are harvested, weighed, and transferred to polypropylene tubes. Place the tube in a calibrated Wizard2 γ-counter (PerkinElmer, Shelton, CT) and count (204 - 274 keV) for 3 minutes. A standard consisting of 1/20 of the injection volume is counted at each time point. The background is automatically subtracted from the count. This standard is also used for decay correction. Calculate % ID/g for each organ collected.

Results and Conclusions:

34A and 34B , a nephroprotectant consisting of 2.5% lysine-arginine is most effective in reducing renal absorption of ^{212 Pb-DOTAMTATE, particularly 1 hour after injection.} Reduced drug absorption in the liver of animals given 2.5% Lys-Arg is also observed. The other agents were not significantly different when compared to the non-nephroprotectant control. This suggests that a combination of positively charged amino acids, 2.5% Lys-Arg, is the most effective way to reduce renal uptake by ^{212 Pb-DOTAMTATE.}

Non-GLP Dose Range Confirmation Study in Athymic Nude Mice

Way:

Female athymic nude mice (~20 g) are injected intravenously with a single dose of 10 μCi, 20 μCi, 40 μCi or 60 μCi of ²¹² Pb-DOTAMTATE or control PBS. Assign 5 animals per treatment group. Animals were weighed 3 times a week and daily for signs of termination criteria (15% weight loss over 2 days, lack of grooming over 5 days, lethargy/weakness over 3 days, reduced mobility, hunched back, diarrhea, hypothermia) monitor The study ends after 4 weeks.

Results and Conclusions:

35 and 36 , acute toxicity is ^{observed at the higher active dose of 212} Pb-DOTAMTATE. In 60 μCi ²¹² Pb-DOTAMTATE, all animals died 7 days after injection, and significant body weight was lost. All animals in the 40 μCi treatment group died 8 days after injection and lost body weight daily until death. In the control, 10 μCi and 20 μCi ²¹² Pb-DOTAMTATE treated groups, 100% of the animals survived and gained weight by the end of the 4-week study, suggesting that the maximum tolerated dose is between 20 μCi and 40 μCi. Based on these data, GLP toxicity studies are initiated at doses of 40 μCi or less.

Intravenous (IV) and intraperitoneal (IP) toxicity studies of free ^{212 PB in mice}

The objective of this study was to evaluate and estimate the acute and chronic toxicity in vivo of ^{free 212} Pb when administered via intravenous or intraperitoneal injection to Balb/c mice. Animals were sacrificed on days 7 (acute) and 90 days (chronic), resulting in acute and delayed occurrence of test article-induced effects, including the effects of a given radionuclide under a “worst case” scenario of total radiolabeled chelation sequestration failure. evaluate Although intravenous injection is not the intended use of radionuclides, both intravenous and intraperitoneal injection routes of administration are studied to overestimate any potential toxicity and identify target organs.

result:

Administration of test article by single IV or IP injection at dose levels of 2.5 μCi or higher was associated with an acute (day 7) significant decrease in hematologic parameters indicative of bone marrow toxicity. In addition, there is renal impairment indicative of radiation-induced nephrotoxicity, possibly with some liver damage at the highest doses. The results in this study indicate that 2.5 μCi is ^{a NOAEL for free 212} Pb in mice for both IV and IP administration routes, with deaths occurring at IV doses of 20 μCi and IP doses of 15 μCi.

No deaths occurred at 2.5, 5, 7.5 and 10 μCi by IV or IP route. However, death occurs on days 11, 40 and 90 (3 of 10 animals) at 15 μCi IP, and on day 16 (2 of 5 animals) at 20 μCi IV. In addition, for the IP route, at 10 μCi at day 69 (1 of 5 animals), at 40 μCi on days 8, 11 and unrecorded days (3 of 4 animals), and at 50 μCi Death occurs on day 9 (3 out of 5 animals). Weight loss was observed 7 days after IV administration at the 20 and 30 μCi doses, and the change is significant when comparing IV doses at 2.5 vs. 30 μCi (P < 0.01) or 7.5 vs. 30 μCi (P <0.05). . Although no further reduction occurred until day 90, the significance of weight loss at 30 μCi persisted at later time points (P < 0.01 for untreated controls). At both time points, body weight is inversely proportional to IV dose level. Although some weight loss was observed even on the 7th day after IP administration at 10 μCi or higher, this effect was not significant. Weight recovery is confirmed by day 90, but at 15 μCi, IP, the attenuation of weight gain begins to become significant (P < 0.05 for untreated controls).

Dose-related decreases in hematological parameters occurred in both IV and IP groups. On day 7, there is a dose-related decrease in mean values for leukocyte and platelet counts after both IV and IP administration starting at the lowest dose level (2.5 μCi). There is partial recovery at 90 days in all groups. In general, clinical chemistry levels remained within the normal range, with the exception of the liver parameters ALT (alanine amino transferase) and AST (aspartate amino transferase), which appeared to be somewhat increased at day 90 in the high dose group. Elongation parameters are within normal limits.

The target organs for this study are bone marrow, kidney and liver. The histopathological findings in this study showed that both IV and IP administrations of test article ≥ 5 μCi were associated with expected reductions in erythroid, myeloid and megakaryocyte series in the bone marrow and were associated with corresponding changes in hematological parameters. indicates that there is There are also changes in the kidney consistent with radiation-induced nephropathy at both days 7 and 90 (Cohen & Robbins, 2003), which over time can lead to irreversible renal failure and anemia due to erythropoietin deficiency. . Although the kidney has substantial capacity for repair, it is a radiation sensitive organ, and irreversible nephrotoxicity can occur with radiation therapy. Changes in the liver, possibly considered treatment-related, are evident at both days 7 and 90, which are associated with increases in ALT and AST at 50 μCi IP at day 90.

conclusion:

^{Administration of 212} Pb by single IV or IP injection at dose levels above 2.5 μCi was associated with a significant reduction in hematological parameters indicative of myeloid toxicity. In addition, there is renal impairment indicative of radiation-induced nephrotoxicity, and possibly some liver damage at the highest doses. The results of this study indicate that 2.5 μCi is a NOAEL for both IV and IP routes of administration, with mortality occurring starting at IV doses of 20 μCi and IP doses of 15, 30, 40 and 50 μCi.

There is no death at 2.5, 5, 7.5 and 10 μCi by IV or IP route. However, death occurs on days 11, 40 and 90 (3 of 10 animals) at 15 μCi IP, and on day 16 (2 of 5 animals) at 20 μCi IV. In addition, for the IP route, at 30 μCi at day 69 (1 of 5 animals), at 40 μCi on days 8, 11 and unrecorded days (3 of 4 animals), and at 50 μCi Death occurs on day 9 (3 out of 5 animals). Of the mice used for hematological bleeds, all mice in the IV-injected group survive the 90-day study period. In the IP-injected group, at 30 μCi on days 69 (1 of 5 animals), at 40 μCi on days 10 and 16 (2 of 5 animals) and at 50 μCi on days 7, 10 and 16 (3, 1 and 1 of 5 animals respectively) death occurs. Weight loss was observed 7 days after IV administration at doses of 20 and 30 μCi; This change is significant when comparing IV dosing at 2.5 versus 30 μCi (P < 0.01) or 7.5 versus 30 μCi (P <0.05). Although no further reduction occurred until day 90, the significance of weight loss at 30 μCi persisted at later time points (P < 0.01 for untreated controls). At both time points, body weight is inversely proportional to IV dose level. Although some weight loss was observed even on the 7th day after IP administration at 10 μCi or higher, this effect was not significant. Weight recovery is confirmed by day 90, but at 15 μCi, IP, the attenuation of weight gain begins to become significant (P < 0.05 for untreated controls).

Significant dose-related decreases in hematological parameters occurred in both the IV and IP groups. At day 7, a dose-related decrease in mean values for WBC and platelet counts is observed after both IV and IP administration, even at the lowest dose level (2.5 μCi). There was partial recovery at day 90 in all groups, but high variability in values (among animals) was observed within groups. In general, clinical chemistry levels remained within the normal range, except for the liver parameters ALT and AST, which appeared to be increased at day 90 in the high-dose group. Elongation parameters are within normal limits. The target organs for this study are bone marrow, kidney and possibly liver. The histopathological findings in this study ^{showed that both IV and IP administrations of 212} Pb ≥ 5 μCi were associated with expected reductions in erythrocytic, myeloid and megakaryocyte series in the bone marrow, and associated with corresponding changes in hematological parameters. indicates that there is There are also changes in the kidney consistent with radiation-induced nephropathy at both days 7 and 90 (Cohen & Robbins, 2003), which over time can lead to irreversible renal failure and anemia due to erythropoietin deficiency. . Although the kidney has substantial capacity for repair, it is a radiation sensitive organ, and irreversible nephrotoxicity can occur with radiation therapy. Changes in the liver, possibly considered treatment-related, are evident at both days 7 and 90, which are associated with increases in ALT and AST at 50 μCi IP at day 90. Experiments are performed with special care in the bladder, lung, intestine and lymphatic system, and no treatment-related results are detected in these other organs. There are no changes considered to be due to (elemental) lead toxicity.

Repeat-dose toxicity

Way:

Female tumor-free CD-1 mice are ^{injected with one dose of 40 μCi 212} Pb-DOTAMTATE, two doses of 20 μCi ²¹² Pb-DOTAMTATE or three doses of 15 μCi ²¹² Pb-DOTAMTATE. For animals receiving multiple treatments, three weeks are given between administrations. Animals were weighed 3 times a week, and termination criteria (15% weight loss or 20% loss from initial body weight over 2 days, lack of grooming over 5 days, lethargy/weakness over 3 days, reduced motility, crooked back, diarrhea, daily monitoring for signs of hypothermia). Blood is collected weekly for hematological analysis.

Results and Conclusions:

A non-GLP repeat dose study is tested for signs of acute toxicity, comparing single versus divided doses (described below). This study is designed based on observations made in athymic nude mice. In athymic nude mice, the 40 µCi dose was severely toxic, with 100% of animals reaching the termination criterion on day 8, and the same toxicity profile was achieved when 40 µCi was administered separately as two injections of 20 µCi at 3-week intervals; Three injections of 15 μCi at 3-week intervals showed no significant or irreversible signs of toxicity. This observation correlates with the GLP results that hematological toxicity is reversible within 1 month in surviving animals from the higher dose group. Because renal and hepatic toxicity is cumulative, single dose treatment versus multiple doses leading to the same cumulative dose should be similar (Barendsen, 1964). Split doses of radiation at 3-week intervals had very similar toxicity profiles compared to single injections. Based on these results, a new study is conducted to compare these three administration modalities in tumor-free CD-1 mice.

A split-dose versus single-dose ²¹² Pb-DOTAMTATE toxicity study is performed in tumor-free CD-1 mice ( FIG. 37 ). Animals are given a single dose of drug, or 2 or 3 cycles of drug every 3 weeks. Nearly 40% of the animals in the 1x40 μCi group died after 9 days of injection, but the surviving animals may survive the rest of the study. In the 2 x 20 μCi group, 50% of animals died within 4 weeks of the study and 1 week after receiving the second dose. Animals that survive the first two injections may survive until the end of the study. The group of animals that received 3x15 μCi of ²¹² Pb-DOTAMTATE did not die. All treated animals did not gain weight to the same extent as untreated controls and appeared to maintain similar body weight throughout the study, except that after each treatment they lost weight and then recovered. Hematological toxicity appears to be the cause of death in the first two groups. Those animals that can recover from the initial toxicity may survive. This is evidenced by low leukocyte counts in the 1 x 40 μCi and 2 x 20 μCi groups after drug injection (Figure 38). Animals receiving a 3×15 μCi dose of ²¹² Pb-DOTAMTATE showed a decrease in their WBC counts, but were able to recover after each administration. This study suggests that divided doses of the drug are optimal because they allow for the same cumulative dose but have recoverable hematological effects.

Biodistribution study of ²¹² PB-DOTATOC in CD-1 mice

Way:

²¹² Pb-DOTATOC is prepared based on the activity required at the time of injection. Add 4.1 ng of peptide per 10 μCi of ^{212 Pb to the tube.} Incubate the mixture at 50° C. for 10 minutes with shaking. The chelation is >95% using ITLC (instant thin layer chromatography). 100 μl of ²¹² Pb-DOTATOC is injected intravenously into the tail of each mouse. Count each organ and control tube using an automatic gamma counter.

result:

Biodistribution is performed using ^{10 μCi of 212} Pb-DOTATOC at 30 min and 4 h in female CD-1 non-tumor bearing mice. The data (FIG. 40) shows rapid drug clearance, with the highest accumulation observed in the kidneys, 19% ID/g observed 30 minutes after injection, and 22% ID/g observed 4 hours after drug injection. These data are consistent with those observed for octreotide derivatives and other isotopes (1,2). In all other organs, almost no drug was detected 4 hours after injection ^{of 212 Pb-DOTATOC.} HPLC is performed for DOTATOC and ^{212 Pb-DOTATOC.} System suitability testing shows that the retention time of DOTATOC is 5.357 minutes ( FIG. 41 ) and natPb-DOTATOC is 5.54 minutes (not shown). ^{HPLC is performed on 212} Pb-DOTATOC, and fractions are collected at 15 second intervals for a total of 10 minutes. Fractions are quantified by an automatic gamma counter and radiometric plots are overlaid on HPLC chromatograms. The maximum radiographic measurements are observed at 6.5 min. This suggests that ²¹² Pb-DOTATOC is within 15% of the retention time observed for low temperature Pb-DOTATOC.

Combination therapy efficacy study in AR42J xenograft-bearing athymic nude mice treated with adrucil ^® and ²¹² PB-DOTAMTATE with treatment cycles of 2 and 3 weeks

Way:

Athymic nude mice are given AR42J tumors and grown until ^{tumors reach approximately 300 mm 3 .} Mice in the treatment group are injected with 100 μl of 15 mg/kg Adrusil ^® once a week for a total of 9 injections. ²¹² Pb-DOTAMTATE at 10 µCi was treated for a total of 3 times at intervals of 2 or 3 weeks. ²¹² Pb-DOTAMTATE is provided within 24 hours of ^{Adrusil ® treatment.} Use 10 μCi per 4.1 ng peptide, and the cumulative injection dose is 30 μCi. Animals are monitored daily, calipered, and weighed 3 times a week. Animals are sacrificed when termination criteria are met.

result:

first injection

2nd injection - 2 weeks group

2nd injection - 3 weeks group

3rd injection - 2 weeks group

3rd injection - 3 weeks group

42 and 43 , ^{animals injected with adrucil ®} alone had a median survival of 2.4 weeks, whereas the saline alone group had a median survival of 3.1 weeks after cell injection. ^{Mice injected with 212} Pb-DOTAMTATE alone 3 times 3 weeks apart had a median survival of 9.14 weeks, whereas ^{combination therapy with Adrusil ®} showed a longer median survival of 11.1 weeks, and 20% of mice He was still alive 21 weeks after the injection. This suggests that ^{the addition of adrucyl ®} radiosensitizer improves median survival by 18% with a 3 week ^{212 Pb-DOTAMTATE treatment cycle.}

Interestingly, better efficacy is observed by reducing the time between injections of ^{212 Pb-DOTAMTATE.} The treatment group receiving 3 x 10 μCi of ²¹² Pb-DOTAMTATE at 2-week intervals had a median survival of 11.9 weeks, and 46% of animals were still maintained 21 weeks after cell injection. The highest efficacy is observed when mice are treated with the radiosensitizers Adrusil ^® and ^{212 Pb-DOTAMTATE at 2-week intervals.} 85% of the animals are still alive after 21 weeks of cell injection, and all tumors are within the limit of quantification ^{of 200 mm 3 .}

Dosimetry and biodistribution of ²⁰³ PB-DOTAMTATE in patients with somatostatin-expressing neuroendocrine tumors.

Way:

A total of 6 patients are enrolled in a first-in-human open-label, single-dose, dosimetry and biodistribution of ^{203 Pb-DOTAMTATE.}

^{All patients (1 female and 5 male) received 203} Pb-DOTAM-TATE at an average dose of 4.94 (4.66 - 5.26) mCi, 1 h, 4 h, 24 h, and 48 h post injection SPECT-CT scan. proceed later. All 6 patients were white.

^{Pharmacokinetic data from 203} Pb-DOTAMTATE imaging is used to calculate absorbed dose from ^{203 Pb-DOTAMTATE imaging.} The data are then extrapolated to calculate the expected tissue absorbed dose after administration of ²¹² Pb-DOTAMTATE for future targeted alpha particle therapy (TAT).

According to the measurement data obtained from the dosimetry of ²⁰³ Pb-DOTAM-TATE, when the Relative Biological Effectiveness (RBE) of 3 is used for the α-particle emission of ²¹² Bi and ^{212 Po, 212} Pb The highest absorbed doses were given by the kidney and liver, with an average of 19 and 17 mGy/MBq, respectively. Experience from external beam radiotherapy has shown that 18-23 Gy for total kidney volume provides a 5% risk of kidney damage within 5 years. The liver can tolerate 27-30 Gy (2 divided doses per day, 1.5 Gy per divided dose). Although the spleen provides the highest absorption capacity, it is not a dose-limiting organ as the spleen is not an essential organ. The doses for bone marrow, lung, heart wall, osteogenic cells and spleen at this administered activity would be 1.6, 2.5, 3.7, 0.5 and 31 Gy, respectively. Except for the spleen, for which toxicity limits have not been widely established, all of these doses are below the toxicity limits for these organs.

^{Comparison of 68} GA-DOTATATE PET/CT and ²⁰³ PB-DOTAMTATE SPECT/CT scans

Reports from these two imaging modalities are independently read by two nuclear medicine physicians without knowledge of the results of other studies in six enrolled patients. A total of 177 lesions in 6 patients ^{were detected by 68} Ga-DOTATATE scans, whereas 109 lesions ^{were detected by 203} Pb-DOTAMTATE. There is a very close correlation between the lesions detected by these two methods (correlation coefficient of 0.89). The total lesions found per organ were similar for visceral (42 versus 38) and nodules (12 versus 13), but not for skeletal lesions (123 versus 58). ⁶⁸ Ga PET/CT scans are more sensitive to detecting axial skeleton (vertebrae, rib cage, and pelvic bones) regions (95 total) compared ^{to 203 Pb-DOTAMTATE (34 total).}

result:

⁶⁸ Ga DOTATATE PET / CT and ²⁰³ Pb-DOTAMTATE SPECT / between the CT has a statistically significant difference is not observed, which is ²⁰³ to assess the eligibility of the ongoing patient an alpha therapy (TAT) targeted by the ²¹² Pb-DOTAMTATE ^{This indicates that 68} Ga DOTATATE can be used instead of Pb-SPECT/CT.

Based on radiometric analysis, the theoretical maximum absorbed capacity estimate for the kidney is 23 Gy, which corresponds to ^{a cumulative dose of 32.7 mCi of 212} Pb-DOTAM-TATE (10.9 mCi per therapy cycle for a total of 3 cycles). do.

The methods herein may be performed in any order and may be repeated as needed.

While the embodiments have been described with reference to various practices and developments, it is to be understood that these embodiments are illustrative, and the scope of the invention is not limited thereto. Many variations, modifications, additions and improvements are possible. For example, all of the techniques described herein or various combinations of some of them may be performed.

Multiple instances may be provided for components, operations, or structures described herein in a single instance. In general, structures and functions presented as separate components in the exemplary configurations may be implemented with the combined structures and components. Similarly, structures and functions presented as a single component may be implemented as separate components. These and other variations, modifications, additions, and improvements may fall within the scope of the present invention.

Insofar as the above description and accompanying drawings disclose any further subject matter not falling within the scope of the claim(s) herein, the present invention is not provided to the public and the right to file one or more applications claiming such additional inventions. is guaranteed Although very narrow claims may be presented herein, it should be recognized that the scope of the invention is much broader than that set forth by the claim(s). A broader claim may be filed in an application claiming priority to this application.

Claims (28)

A cancer targeting composition for treating cancer cells overexpressing a somatostatin receptor, comprising a molecule of formula (I) or a pharmaceutically acceptable salt thereof.
Formula (I) M-Ch-L ₁ -Tm
here,
M is a radioisotope selected from the group consisting ^{of 212} Pb and ^{203 Pb;}
Ch is a chelator having the structure of formula (V):
Formula (V)

here,
R ⁵ , R ⁶ and R ⁸ are each independently (C ₁ -C ₆ )alkyl-C(=O)-N(-R ²⁵ )-R ²⁶ ;
R ⁹ , R ¹⁰ , R ¹¹ , R ¹² , R ¹⁵ , R ¹⁶ , R ¹⁷ , R ¹⁸ , R ¹⁹ , R ²⁰ , R ²¹ , R ²² , R ²³ and R ²⁴ are each independently H, D, F , Cl and (C ₁ -C ₆ )alkyl;
R ⁷ is selected from the group consisting of (C ₁ -C ₆ )alkyl-C(=O)-N(-R ²⁵ )-R ²⁶ and L _{1 ;}
R ¹³ and R ¹⁴ are each independently selected from the group consisting of H, D, F, Cl, (C ₁ -C ₆ )alkyl and L ^{1 ;}
R ²⁵ and R ²⁶ are each independently selected from the group consisting of H, D, (C ₁ -C ₆ )alkyl and (C ₁ -C ₆ )alkyl-C(=O)-OH;
L ¹ is (C ₁ -C ₆ )alkyl-C(=O)-NH-(C ₁ -C ₆ )alkyl-C(=O)-NH, (C ₁ -C ₆ )alkyl-(C ₆ H ₄ )-NH-C(=S)-NH, C(-CO ₂ H)-(C ₁ -C ₆ )alkyl-(C ₆ H ₄ )-NH-C(=S)-NH, (C ₁ to -C ₆ )alkyl-C(=O)-NH, (C ₁ -C ₆ )alkyl-C(=O)-(O-CH ₂ -CH ₂ ) _1-20 -C(=O)-NH is selected from the group consisting of;
Tm has the structure of formula (VI):
Formula (VI)

wherein R ²⁷ is selected from the group consisting of CH ₂ -OH and C(=O)-OH;
However, only one of R ⁷ , R ^{13 ,} or R ¹⁴ is L ¹ . The composition of claim 1 , wherein the molecule of formula (I) has a structure represented by formula (VII).
Formula (VII)

here,
M is a radioisotope selected from the group consisting ^{of 212} Pb and ^{203 Pb;}
R ⁵ , R ⁶ and R ⁸ are each independently (C ₁ -C ₆ )alkyl-C(=O)-N(-R ²⁵ )-R ²⁶ ;
R ⁹ , R ¹⁰ , R ¹¹ , R ¹² , R ¹⁵ , R ¹⁶ , R ¹⁷ , R ¹⁸ , R ¹⁹ , R ²⁰ , R ²¹ , R ²² , R ²³ and R ²⁴ are each independently H, D, F , Cl and (C ₁ -C ₆ )alkyl;
R ¹³ and R ¹⁴ are each independently selected from the group consisting of H, D, F, Cl and (C ₁ -C _{6 )alkyl;}
R ²⁵ and R ²⁶ are each independently selected from the group consisting of H, D, (C ₁ -C ₆ )alkyl and (C ₁ -C ₆ )alkyl-C(=O)-OH;
L ¹ is (C ₁ -C ₆ )alkyl-C(=O)-NH-(C ₁ -C ₆ )alkyl-C(=O)-NH, (C ₁ -C ₆ )alkyl-(C ₆ H ₄ )-NH-C(=S)-NH, C(-CO ₂ H)-(C ₁ -C ₆ )alkyl-(C ₆ H ₄ )-NH-C(=S)-NH, (C ₁ to -C ₆ )alkyl-C(=O)-NH and (C ₁ -C ₆ )alkyl-C(=O)-(O-CH ₂ -CH ₂ ) _1-20 -C(=O)-NH is selected from the group consisting of;
wherein R ²⁷ is selected from the group consisting of CH ₂ -OH and C(=O)-OH. The composition of claim 1 , wherein the molecule of formula (I) has the structure represented by formula (VIII).
Formula (VIII)

here,
M is a radioisotope selected from the group consisting ^{of 212} Pb and ^{203 Pb;}
R ⁵ , R ⁶ and R ⁸ are each independently selected from the group consisting _{of (C 1} -C ₆ )alkyl-C(=O)-N(-R ²⁵ )-R ^{26 ;}
R ⁹ , R ¹⁰ , R ¹¹ , R ¹² , R ¹⁵ , R ¹⁶ , R ¹⁷ , R ¹⁸ , R ¹⁹ , R ²⁰ , R ²¹ , R ²² , R ²³ and R ²⁴ are each independently H, D, F , Cl and (C ₁ -C ₆ )alkyl;
R ⁷ is (C ₁ -C ₆ )alkyl-C(=O)-N(-R ²⁵ )-R ²⁶ ;
R ¹³ is selected from the group consisting of H, D, F, Cl and (C ₁ -C _{6 )alkyl;}
R ²⁵ and R ²⁶ are each independently selected from the group consisting of H, D, (C ₁ -C ₆ )alkyl and (C ₁ -C ₆ )alkyl-C(=O)-OH;
L ¹ is (C ₁ -C ₆ )alkyl-(C ₆ H ₄ )-NH—C(=S)—NH;
wherein R ²⁷ is selected from the group consisting of CH ₂ -OH and C(=O)-OH. The composition of claim 1 , wherein the molecule of formula (I) has the structure represented by formula (IX).
Formula (IX)

here,
M is a radioisotope selected from the group consisting ^{of 212} Pb and ^{203 Pb;}
R ⁵ , R ⁶ and R ⁸ are each independently (C ₁ -C ₆ )alkyl-C(=O)-N(-R ²⁵ )-R ²⁶ ;
R ⁹ , R ¹⁰ , R ¹¹ , R ¹² , R ¹⁵ , R ¹⁶ , R ¹⁷ , R ¹⁸ , R ¹⁹ , R ²⁰ , R ²¹ , R ²² , R ²³ and R ²⁴ are each independently H, D, F , Cl and (C ₁ -C ₆ )alkyl;
R ¹³ and R ¹⁴ are each independently selected from the group consisting of H, D, F, Cl and (C ₁ -C _{6 )alkyl;}
R ²⁵ and R ²⁶ are each independently selected from the group consisting of H, D, (C ₁ -C ₆ )alkyl and (C ₁ -C ₆ )alkyl-C(=O)-OH;
wherein R ²⁷ is selected from the group consisting of CH ₂ -OH and C(=O)-OH. 3. The cancer targeting composition of claim 2, wherein the molecule of formula (I) has a structure represented by the formula

4. The cancer targeting composition of claim 3, wherein the molecule of formula (I) has a structure represented by the formula

The composition of claim 1 , wherein the molecule of formula (I) has the structure of formula (X).
Formula (X)

here,
M is a radioisotope selected from the group consisting ^{of 212} Pb and ^{203 Pb;}
R ⁵ , R ⁶ and R ⁸ are each independently (C ₁ -C ₆ )alkyl-C(=O)-N(-R ²⁵ )-R ²⁶ ;
R ⁹ , R ¹⁰ , R ¹¹ , R ¹² , R ¹⁵ , R ¹⁶ , R ¹⁷ , R ¹⁸ , R ¹⁹ , R ²⁰ , R ²¹ , R ²² , R ²³ and R ²⁴ are each independently H, D, F , Cl and (C ₁ -C ₆ )alkyl;
R ⁷ is selected from the group consisting of H, D, F, Cl, (C ₁ -C ₆ )alkyl and (C ₁ -C ₆ )alkyl-C(=O)-N(-R ²⁵ )-R ^{26 and} ;
R ¹³ is selected from the group consisting of H, D, F, Cl and (C ₁ -C _{6 )alkyl;}
R ²⁵ and R ²⁶ are each independently selected from the group consisting of H, D, (C ₁ -C ₆ )alkyl, and (C ₁ -C ₆ )alkyl-C(=O)-OH;
wherein R ²⁷ is selected from the group consisting of CH ₂ -OH and C(=O)-OH. The cancer targeting composition of any one of claims 1 to 7; and
at least one of a pharmaceutically acceptable buffer, antioxidant and scavenger
A cancer targeting kit for treating cancer cells overexpressing a somatostatin receptor, comprising a. delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete

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